Method and system for controllably administering fluid to a patient and/or for controllably withdrawing fluid from the patient

ABSTRACT

Method and system for controllably administering and/or withdrawing fluid from a patient. In one embodiment, the system may include an infusion needle, a pump adapted to be operably coupled to the infusion needle for creating fluid flow through the infusion needle, and a hands-free switch for activating and/or deactivating the pump.

RELATED APPLICATIONS

This application claims the benefit to U.S. patent application Ser. No.14/777,119 filed on Sep. 15, 2015, which is a national stage filing ofInternational Patent Application No.: PCT/US2014/030339, filed Mar. 17,2014, which claims priority to U.S. Provisional Application No.61/790,481 filed on Mar. 15, 2013, the entire contents of both of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to the administration of fluidto a patient or to the withdrawal of fluid from a patient and relatesmore specifically to a method and system for controllably administeringfluid to a patient and/or for controllably withdrawing fluid from thepatient.

There are many situations in which it may be desirable to administer oneor more fluids to a patient or to withdraw one or more fluids from apatient. An example of one such situation involves the administration ofregional anesthesia to a patient. In contrast to general anesthesia,which is a systemic sedation of a patient, regional anesthesia is theadministration of medication to specific body regions by anesthetizingspecific nerves, thereby permitting the patient to block pain and to becognitively alert or conscious. Regional anesthesia may be used to treatpain during surgery and during post-surgery recovery and may also beused to provide patients with extended relief of longer-term pain.Because regional anesthesia is not systemic, regional anesthesiaincrease patient safety and satisfaction and, concurrently, reducesanesthesia cost. Regional anesthesia is an effective technique forselectively anesthetizing a specific region of the body withoutinterfering with a patient's vital systems.

Traditionally, regional anesthesia involves the use of a specialtyregional anesthesia needle, which the physician uses to infusemedication in close proximity to the target nerves to be blocked, i.e.,anesthetized. The physician may insert the needle blindly, usinganatomical landmarks of the patient in an attempt to locate the nerve tobe blocked. If the needle tip is more than 5 mm from the nerve, theanesthesia may be ineffective. If the needle tip touches the nerve, suchcontact of the nerve by the needle tip may cause nerve damage. Witheffective manual needle insertion and infusion, the patient experiencesparesthesia, a buzzing tingling sensation, which is usually orallyreported by the patient to the physician.

As can be appreciated, the success rate of a blindly-located nerve blockis lowered if the patient's feedback to the physician during the needleinsertion procedure is inaccurate or if the patient is disoriented orunresponsive. To minimize the likelihood of an errant positioning of theinfusion needle, certain devices have been used to help position theneedle in proximity to the body portion that one wishes to target. Onesuch device is a nerve stimulator, which provides electrical current tothe infusion needle and which causes a body portion contacted by theneedle to twitch, thereby providing a visual indicator to the physicianof the location of the needle. Examples of nerve stimulators aredisclosed in the following documents, all of which are incorporatedherein by reference: U.S. Pat. No. 5,284,153, inventors Raymond et al.,issued Feb. 8, 1994; U.S. Patent Application Publication No. US2007/0213771 A1, inventors Spinner et al., published Sep. 13, 2007; U.S.Patent Application Publication No. US 2004/0059247 A1, inventor Urmey,published Mar. 25, 2004; European Patent Application Publication No. EP0 957 982 A1, published Nov. 24, 1999; and European Patent ApplicationPublication No. EP 0 637 934 A1, published Feb. 15, 1995.

Another device that is commonly used, either in place of a nervestimulator or in combination therewith, to help position in infusionneedle in proximity to a body portion that one wishes to target is ahandheld ultrasonic imager. Examples of handheld ultrasonic imagers aredisclosed in the following documents, all of which are incorporatedherein by reference: U.S. Pat. No. 8,257,262 B2, inventors Petersen etal., issued Sep. 4, 2012; U.S. Pat. No. 7,645,238 B2, inventor Hirsch,issued Jan. 12, 2010; and U.S. Patent Application Publication No. US2007/0073155 A1, inventors Park et al., published Mar. 29, 2007.

One of the shortcomings associated with administering regionalanesthesia to a patient in the manner described above is that typicallymore than one person is needed to perform the procedure. This isbecause, for example, the physician may use one hand or both hands toposition the needle in the patient or may use one hand to position theneedle in the patient and may use another hand to hold a handheldultrasonic imager, a nerve stimulator, or another device used to helplocate the needle in the patient. As a result, a nurse or otherassistant is typically needed to operate the syringe or other fluid flowdevice coupled to the infusion needle, typically by a length of tubing,so that the desired quantity of anesthesia may be dispensed through theinfusion needle.

In addition, despise the advent of techniques to help position theneedle correctly, the needle tip may inadvertently be inserted into anerve. As can be appreciated, if insertion of the needle tip into anerve occurs, any subsequent injection of anesthesia into the nerve maycause significant injury to the nerve. Such injury to the nerve can beeither mechanical or ischemic trauma due to an increase in endoneuralpressure caused by the fluid injected and/or endoneural edema. In viewof the above, current recommendations are for the syringe operator toavoid high injection pressures. However, a determination of when aninjection pressure is, in fact, dangerously high has traditionally beenbased simply on a subjective feel of the syringe by the syringeoperator, without any accompanying objective measurement of the actualinjection pressure. Such a subjective assessment by the syringe operatoris further complicated by the differences in hand strength amongdifferent users and by the multitude of needle types, needle lengths,and needle lumen calibers, all of which can affect an interpretation ofwhat is too forceful or too fast.

In an attempt to address some, but not all, of the above issues, thereis disclosed a method and apparatus to decrease the risk intraneuronalinjection during administration of nerve block anesthesia in U.S. Pat.No. 6,866,648 B2, inventors Hadzic et al., issued Mar. 15, 2005, whichis incorporated herein by reference. More specifically, theaforementioned patent teaches the provision of a pressure sensing devicelocated between an injection device (typically a syringe) and a nerveblock needle whereby injection pressure during a nerve block injectioncan be easily and objectively monitored, thereby allowing the operatorto monitor the injection pressure and/or injection speed during a nerveblockage injection procedure and to take appropriate corrective actionsif abnormal pressure conditions are observed.

Other document that may be of interest include the following, all ofwhich are incorporated herein by reference: U.S. Pat. No. 7,727,224 B2,inventor Hadzic et al., issued Jun. 1, 2010; U.S. Pat. No. 7,689,292 B2,inventors Hadzic et al., issued Mar. 30, 2010; U.S. Pat. No. 5,910,135,inventors Hadzic et al., issued Jun. 8, 1999; U.S. Pat. No. 5,830,151,inventors Hadzic et al., issued Nov. 3, 1998; PCT InternationalPublication No. WO 2012/139035 A1, published Oct. 11, 2012; EuropeanPatent Application Publication. No. EP 1 599 135 A2, published Nov. 30,2005; Steinfeldt et al., “Forced Needle Advancement During Needle-NerveContact is a Porcine Model: Histological Outcome,” Anesth. Analg.,113:417-20 (2011); ASRA News, May 2009 Newsletter, a Publication of theAmerican Society of Regional Anesthesia and Pain Medicine; Theron etal., “An Animal Model of ‘Syringe Feel’ Daring Peripheral Nerve Block,”Reg. Anesth. Pain Med., 34(4):330-2 (2009); Robards et al., “IntraneuralInjection with Low-Current Stimulation During Popliteal Sciatic NerveBlock,” Anesth Analog., 109:673-7 (2009); Gerancher et al., “Developmentof a Standardized Peripheral Nerve Block Procedure Note Form,” Reg.Anesth. Pain Med., 30(1):67-71 (2005); Claudio et al., “InjectionPressures by Anesthesiologist During Simulated Peripheral Nerve Block,”Reg. Anesth. Pain Med., 29(3):201-5 (2004); Hadzic et al., “Combinationof Intraneural Injection and High Injection Pressure Leads to FascicularInjury and Neurologic Deficit in Dogs,” Reg. Anesth. Pain Med.,29(5):417-23 (2004); Auroy et al., “Major Complications of RegionalAnesthesia in France,” Anesthesiology, 97:1274-80 (2002); Urmey et al.,“Inability to Consistently Elicit a Motor Response following SensoryParesthesia during Interscalene Block Administration,” Anesthesiology,96:552-4 (2002); Borgeat et al., “Evaluation of the Lateral ModifiedApproach for Continuous Interscalene Block after Shoulder Surgery,”Anesthesiology. 99:436-42 (2003); and ASRA News, May 2007 Newsletter, aPublication of the Americas Society of Regional Anesthesia and PainMedicine.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a new method andsystem for controllably administering fluid to a patient and/or forcontrollably withdrawing fluid from the patient.

It is another object of the present invention to provide a method andsystem as described above that overcomes at least some of thedeficiencies of existing methods and systems.

According to one aspect of the invention, there is provided a system forcontrollably administering fluid to a patient and/or for controllablywithdrawing fluid from the patient, the system comprising a syringecomprising a plunger with a first mechanical interface; and a syringebody for holding fluids. The system further includes a pump comprising asecond mechanical interface which interfaces with the plunger of thesyringe via the first mechanical interface thereby to advance theplunger relative to the body of the syringe to controllably administerfluid to a patient; and to retract the plunger of said syringe relativeto the body of said syringe to controllably withdraw fluid from thepatient.

According to another aspect of the invention, there is provided a systemfor controllably administering fluid to a patient and/or forcontrollably withdrawing fluid from the patient, the system comprising(a) a syringe, the syringe comprising a syringe body and a syringeplunger; (b) an infusion needle, the infusion needle being operativelycoupled to the syringe; (c) a pump, the pump comprising a motor and agear, the gear being engageable with the syringe plunger to drivemovement of the syringe plunger relative to the syringe body; (d) anadaptor for selectively engaging the gear and the syringe plunger; and(e) a hands-free switch for activating and/or deactivating the motor.

According to still another aspect of the invention, there is provided amethod for controllably administering fluid to a patient and/or forcontrollably withdrawing fluid from the patient, the method comprising(a) providing the above-described system; (b) positioning the infusionneedle at a desired location within the patient; (c) using thehands-free switch to activate and to deactivate the pump. In a further,more detailed aspect of the invention, the system may further comprise acontrol device for automatically preventing the fluid pressure in theinfusion needle from exceeding a predetermined threshold.

According to yet another aspect of the invention, there is provided afoot-operable switch, the foot-operable switch comprising (a) aresiliently-compressible tube having a void; (b) aresiliently-compressible circuit roll disposed in the void, theresiliently-compressible circuit roll comprising a sheet ofelectrically-insulating material and two electrically-conductiveelements on the sheet of electrically-insulating material, the twoelectrically-conductive elements being arranged on the sheet so as tomake contact with one another when the resiliently-compressible tube iscompressed.

According to still yet another aspect of the invention, there isprovided a kit, the kit comprising (a) a first container; (b) a syringedisposed within the first container; (c) a pump disposed within thefirst container, the pump being adapted to pump fluid into and/or out ofthe syringe; and (d) a second container, the first container beingdisposed within the second container, the second container being ablister pack container into which is incorporated at least one footpedal adapted for operating the pump.

According to a further aspect of the invention, there is provided a kit,the kit comprising (a) a first container; (b) a syringe disposed withinthe first container; (c) a pump disposed within the first container, thepump being adapted to pump fluid into and/or out of the syringe; and (d)a foot pedal adapted for operating the pump.

For purposes of the present specification and claims, various relationalterms like “top,” “bottom,” “proximal,” “distal,” “upper,” “lower,”“front,” and “rear” are used to describe the present invention when saidinvention is positioned in or viewed from a given orientation. It is tobe understood that, by altering the orientation of the invention,certain relational terms may need to be adjusted accordingly.

Additional objects, as well as features and advantages, of the presentinvention will be set forth in part in the description which follows,and in part will be obvious from the description or may be learned bypractice of the invention. In the description, reference is made to theaccompanying drawings which form a part thereof and in which is shown byway of illustration various embodiments for practicing the invention.The embodiments will be described in sufficient detail to enable thoseskilled in the art to practice the invention, and it is to be understoodthat other embodiments may be utilized and that structural changes maybe made without departing from the scope of the invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is best defined by the appendedclaims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings, which are hereby incorporated into andconstitute a part of this specification, illustrate various embodimentsof the invention and, together with the description, serve to explainthe principles of the invention. In the drawings wherein like referencenumerals represent like parts:

FIG. 1 is a schematic representation of a first embodiment of a systemaccording to the present invention for controllably administering fluidto a patient and/or for controllably withdrawing fluid from the patient;

FIG. 2 is a perspective view, partly schematic, of a second embodimentof a system according to the present invention for controllablyadministering fluid to a patient and/or for controllably withdrawingfluid from the patient;

FIGS. 3(a) and 3(b) are perspective and partly exploded perspectiveviews, respectively, of the syringe/pump assembly of FIG. 2 ;

FIG. 4 is a perspective view of the syringe/pump assembly of FIG. 2 ,with the housing cover not being shown to reveal certain internalcomponents;

FIGS. 5(a) and 5(b) are enlarged distal perspective and enlargedproximal perspective views, respectively, of the syringe body shown inFIG. 3(b);

FIGS. 6(a) and 6(b) are enlarged distal perspective and enlargedproximal perspective views, respectively, of the syringe plunger shownin FIG. 3(b);

FIGS. 7(a) and 7(b) are enlarged distal perspective and enlargedproximal perspective views, respectively, of the seal shown in FIG.3(b);

FIGS. 8(a) and 8(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the housing body shown in FIG. 3(b);

FIGS. 9(a) and 9(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the housing cover shown in FIG.3(b);

FIG. 10 is an enlarged top perspective view of the clip shown in FIG.3(b);

FIGS. 11(a) and 11(b) are enlarged lop perspective and enlarged bottomperspective views, respectively, of the motor carrier shown in FIG.3(b);

FIGS. 12(a) and 12(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the friction plate shown in FIG.3(b);

FIG. 13 is an enlarged perspective view of the motor shown in FIG. 3(b);

FIGS. 14(a) and 14(b) are enlarged front perspective and enlarged rearperspective views, respectively, of the gear shown in FIG. 3(b);

FIGS. 15(a) and 15(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the rotary actuator shown in FIG.3(b);

FIGS. 16(a) and 16(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the knob shown in FIG. 3(b);

FIG. 17 is a simplified schematic representation of a first exemplaryembodiment of the control device of FIG. 2 , the first exemplaryembodiment of the control device being shown as part of a simplifiedrendering of the system of FIG. 2 ;

FIG. 18 is a simplified schematic representation of an experimentalset-up used to measure the pressure generated by a small electric motorused in a prototype of the syringe/pump assembly of FIG. 2 for driving a20 mL syringe whose output was occluded;

FIG. 19 is a graph depicting the pressure measured as a function ofresistance added using the experimental set-up of FIG. 18 ;

FIG. 20 is a graph depicting the flow rates measured when replacing theocclusion cap in the experimental set-up of FIG. 18 with various needletypes and using an 18-ohm resistor as the control device;

FIG. 21 is a simplified schematic representation a second exemplaryembodiment of the control device of FIG. 2 , the second exemplaryembodiment of the control device being shown as part of a simplifiedrendering of the system of FIG. 2 ;

FIG. 22 is a simplified schematic representation of a third exemplaryembodiment of the control device of FIG. 2 , the third exemplaryembodiment of the control device being shown as part of a simplifiedrendering of the system of FIG. 2 ;

FIG. 23 is a partly exploded perspective view of as alternate foot pedalfor use in the system of FIG. 2 ;

FIG. 24 is a perspective view of a kit comprising two of the foot pedalsof FIG. 23 , together with certain components of the system of FIG. 2 ;

FIGS. 25(a) and 25(b) are perspective and partly exploded perspectiveviews, respectively, of a foot pedal assembly tor use in the system ofFIG. 2 ;

FIGS. 26(a) and 26(b) are views of one of the resiliently-compressiblecircuit rolls of FIG. 25(b) shown in rolled and unrolled states,respectively;

FIG. 27 is a perspective view, partly schematic, of a third embodimentof a system according to the present invention for controllablyadministering fluid to a patient and/or for controllably withdrawingfluid from the patient;

FIG. 28 is an enlarged bottom perspective view of the peristaltic pumpshown in FIG. 27 , together with its associated cable and connector;

FIG. 29 is an exploded perspective view of the peristaltic pump shown inFIG. 27 ;

FIGS. 30(a) and 30(b) are side views of the peristaltic pump shown inFIG. 27 , with a portion of the housing not being shown and with thetube stop positioned in engagement with and disengaged fromrespectively, the silicone tubing;

FIGS. 31(a) and 31(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the motor cover shown in FIG. 29 ;

FIGS. 32(a) and 32(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the housing body shown in FIG. 29 ;

FIGS. 33(a) and 33(b) are enlarged perspective views, respectively, ofthe housing cover shown in FIG. 29 ;

FIG. 34 is tar enlarged perspective view of the motor shown in FIG. 29 ;

FIGS. 35(a) and 35(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the motor magnet shown in FIG. 29 ;

FIGS. 36(a) and 36(b) are enlarged top perspective and enlarged bottomperspective views, respectively, of the upper magnet washer shown inFIG. 29 ;

FIG. 37 is an enlarged perspective view of the roller shown in FIG. 29 ;

FIG. 38 is an enlarged perspective view of the silicone tubing shown inFIG. 29 ;

FIGS. 39(a) and 39(b) are enlarged proximal perspective and enlargeddistal perspective views, respectively, of the male luer shown in FIG.29 ;

FIGS. 40(a) and 40(b) are enlarged proximal perspective and enlargeddistal perspective views, respectively, of the female luer shown in FIG.29 ;

FIG. 41 is an enlarged perspective view of the knob shown in FIG. 29 ;

FIGS. 42(a) and 42(b) are enlarged front perspective and enlarged rearperspective views, respectively, of the tube stop shown in FIG. 29 ;

FIG. 43 is a perspective view, partly schematic, of a fourth embodimentof a system according to the present invention for controllablyadministering fluid to a patient and/or for controllably withdrawingfluid from the patient;

FIG. 44 is a perspective view, partly schematic, of a fifth embodimentof a system according to the present invention for controllablyadministering fluid to a patient and/or for controllably withdrawingfluid from the patient;

FIG. 45 is a perspective view, partly schematic, of a sixth embodimentof a system according to the present invention for controllablyadministering fluid to a patient and/or for controllably withdrawingfluid from the patient;

FIGS. 46(a) and 46(b) are perspective views of the syringe/pump assemblyof FIG. 45 , showing the syringe and the pump coupled to one another viathe adaptor and decoupled from one another, respectively;

FIG. 46(c) is a partly exploded perspective view of the syringe/pumpassembly of FIG. 45 ;

FIG. 47 is a perspective view of the syringe plunger shown in FIG. 45 ;

FIGS. 48(a) through 48(e) are top perspective, bottom perspective, top,bottom, and longitudinal section views, respectively, of the pumphousing body shown in FIG. 45 ;

FIGS. 49(a) through 49(e) are top perspective, bottom perspective, top,bottom, and longitudinal section views, respectively, of the pumphousing cover shown in FIG. 45 ;

FIGS. 50(a) through 50(d) are top perspective, bottom perspective, side,and longitudinal section views, respectively, of the locking clip shownin FIG. 45 ;

FIGS. 51(a) and 51(b) are top perspective and bottom perspective views,respectively, of the gear shown in 46(c);

FIGS. 52(a) through 52(c) are top perspective, bottom perspective, andbottom views, respectively, of the top portion of the adaptor shown inFIG. 45 ;

FIGS. 53(a) through 53(c) are bottom perspective, top perspective, andbottom views, respectively, of the bottom portion of the adaptor shownin FIG. 45 ;

FIGS. 54(a) and 54(b) are fragmentary perspective and fragmentary partlyexploded perspective views, respectively, of the foot pedal assemblyshown in FIG. 45 ;

FIG. 55 is a fragmentary, partly schematic, section view of a firstalternate syringe for use in the system of FIG. 45 , the first alternatesyringe comprising a first embodiment of a fluid pressure sensingdevice;

FIG. 56 is a fragmentary, partly schematic, section view of a secondalternate syringe tor use in the system of FIG. 45 , the secondalternate syringe comprising a second embodiment of a fluid pressuresensing device;

FIG. 57 is a fragmentary, partly schematic, section view of a thirdalternate syringe for use in the system of FIG. 45 , the third alternatesyringe comprising a third embodiment of a fluid pressure sensingdevice; and

FIGS. 58(a) and 58(b) are exploded perspective and longitudinal sectionviews, respectively, of a fourth alternate syringe for use in the systemof FIG. 45 , the fourth alternate syringe comprising a fourth embodimentof a fluid pressure sensing device, the syringe being shown incombination with an adaptor.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed at a method sod system forcontrollably administering fluid to a patient and/or for controllablywithdrawing fluid from the patient. An exemplary and non-limitingapplication of the method and system of the present invention is in thefield of regional anesthesia, where the method and system may be used toinject an anesthetizing fluid into a specific region of the patient, forexample, to effect a nerve blockage. In addition, the method and systemof the present invention may also be used to aspirate fluid from thepatient, for example, to ascertain whether a needle that has beeninserted into the patient in order to administer anesthesia to a nervehas been properly placed or has been misplaced, for example, its a bloodvessel. The aforementioned injection and aspiration procedures of thepresent method and system can be performed on the same patient, albeitsequentially, as opposed to simultaneously.

Referring now to FIG. 1 , there is schematically shown a firstembodiment of a system according to the present invention forcontrollably administering fluid to a patient and/or for controllablywithdrawing fluid from the patient, the system being representedgenerally by reference numeral 11. System 11 is shown in FIG. 1 beingused by a doctor D on a patient P.

System 11 may include one or more of an infusion needle assembly 13, ahandheld ultrasound imager 15, a fluid supply storage unit 17, a wastestorage unit 18, a fluid pump 19, a first foot pedal 21, and a secondfoot pedal 23. Each of the foregoing components will now be discussedfurther below.

Infusion needle assembly 13 may be conventional and may include aninfusion needle 25 and a needle hub 27. Infusion needle 25, which may bea generally tubular member having a sharpened distal end 29, may have alength of, for example, approximately 25 mm to approximately 150 mm andmay have an outer diameter of, for example, approximately 25 gauge toapproximately 18 gauge. Needle hub 27, which may be a generally tubularor otherwise finger graspable member, may be coaxially positioned aroundand fixed to infusion needle 25. In use, doctor D may grasp needle hub27 in a first hand H.sub.1, then may insert distal end 29 of infusionneedle 25 into patient P through a desired entry site, and then mayguide distal end 29 of infusion needle 25 to a desired destinationwithin the body of patient P.

Handheld ultrasound imager 15 may be conventional and may be used bydoctor D to observe, in real-time, on a monitor 31 the location ofinfusion needle 25 within patient P. In use, doctor D may hold a probe33 of handheld ultrasound imager 15 in a second hand H.sub.2 and mayposition probe 33 against patient P so that infusion needle 25 may beobserved on monitor 31. (Although not shown in FIG. 1 , infusion needleassembly 13 may alternatively or additionally include a nerve stimulatorlead, which may be connected at one end to infusion needle 25 and at anopposite end to a source of electrical current and which may be used tocause a body portion contacted by infusion needle 25 to involuntarilytwitch, thereby providing a visual indicator to the doctor of thelocation of infusion needle 25. One hand of the doctor may be used toguide and to provide fine control of distal end 29 of infusion needle25, and the other hand may be used to adjust the stimulator.)

Fluid supply storage unit 17 may be a receptacle suitable for holding aquantity of the fluid one wishes to inject into patient P throughinfusion needle 25. Fluid supply storage unit 17 may comprise, forexample, a syringe, a fluid pouch, such as an I.V. bag, or some otherfluid receptacle. Fluid supply storage unit 17 may hold a quantity of asuitable fluid, which fluid may be, for example, a conventionalanesthetizing fluid.

Waste storage unit 18 may be a suitable receptacle for holding aquantity of the fluid one wishes to withdraw from patient P throughinfusion needle 25. Waste storage unit 18 may comprise, for example, asyringe, a fluid pouch, or some other fluid receptacle.

If desired, for example, depending on the type of procedure beingperformed, the same receptacle may be used, albeit at different pointsin time, both as fluid supply storage unit 17 and as waste storage unit18.

Fluid pump 19 may be a bi-directional pumping device that may be adaptedso cause fluid to flow from fluid supply storage unit 17 to infusionneedle 25 and that may alternatively be adapted to cause fluid to flowfrom infusion needle 25 to waste storage unit 18. More specifically,when used in one mode of operation, fluid pump 19 may cause fluid toflow from fluid supply storage unit 17 to infusion needle 25, and, whenused in another mode cooperation, fluid pump 19 may cause fluid to flowfrom infusion needle 25 to waste storage unit 18. Fluid pump 19 may bepositioned, as shown, in-line between fluid supply storage unit 17 andinfusion needle assembly 13 using a first tubing 35 and a second tubing37 and in-line between waste storage unit 18 and infusion needleassembly 13 using first tubing 35 and a third tubing 39. (Where the samereceptacle is used as fluid supply storage unit 17 and as waste storageunit 18, third tubing 39 may be eliminated.) Alternatively, instead ofbeing positioned in-line between fluid supply storage unit 17 andinfusion needle assembly 13 and in-line between waste storage unit 18and infusion needle assembly 13, fluid pump 19 may be positionedelsewhere, for example, so that fluid supply storage unit 17 ispositioned between fluid pump 19 and needle infusion assembly 13 and sothat waste storage unit 18 is positioned between fluid pump 19 andneedle infusion assembly 13.

Fluid pump 19 may be electrically powered, for example, usingalternating current or direct current (e.g., one or more batteries).Fluid pump 19 may include some mechanism for shutting down (i.e.,stopping operation or stalling) when the fluid pressure within the fluidpath exceeds some predetermined threshold value. In this manner, forexample, if infusion needle 25 experiences an unexpected blockage, suchas may occur if infusion needle 25 is inadvertently inserted into anerve, thereby causing the field pressure within the fluid path toexceed the predetermined threshold value, fluid pump 19 will stoppumping fluid from fluid supply storage unit 17 to needle 25. Wheresystem 11 is being used to anesthetize a nerve, the threshold value forshutting down fluid pump 19 may be, for example, approximately 10 psi toapproximately 20 psi, preferably approximately 15 psi to approximately20 psi. The shutdown mechanism for fluid pump 19 may comprise, forexample, arty mechanism (e.g., mechanical, electrical,electromechanical, magnetomechanical, etc.) that is triggered when thefluid pressure within the fluid path exceeds the predeterminedthreshold.

First foot pedal 21 may be coupled to fluid pump 19 in such a way thatactuation of first foot pedal 21 causes fluid pump 19 to operate bypumping fluid from fluid supply storage unit 17 to infusion needle 25.Where fluid pump 19 is a pump of the type that is electrically powered,first foot pedal 21 may be connected to fluid pump 19 by a wire 41 andmay be used to close a switch that causes fluid pump 19 to pump fluidfrom fluid supply storage unit 17 to infusion needle 25. First footpedal 21 may be a conventional foot pedal but is not limited to aconventional foot pedal and may encompass any switching mechanism thatmay be operated by foot.

Second foot pedal 23 may be coupled to fluid pump 19 in such a way thatactuation of second foot pedal 23 causes fluid pump 19 to operate bypumping fluid from infusion needle 25 to waste storage unit 18. Wherefluid pump 19 is a pump of the type that is electrically powered, secondfoot pedal 23 may be connected to fluid pump 19 by a wire 43 and may beused to close a switch that causes fluid pump 19 to pump fluid frominfusion needle 25 to waste storage unit 18. Second foot pedal 23 may bea conventional foot pedal but is not limited to a conventional footpedal and may encompass any switching mechanism that may be operated byfoot.

Although first foot pedal 21 and second foot pedal 23 are shown in FIG.1 being coupled to fluid pump 19 by wires 41 and 43, respectively, itcan readily be appreciated that wires 41 and 43 may be replaced by anywireless means including, but not limited to, using Bluetoothcommunications to connect foot pedals 21 and 23 to fluid pump 19 orusing voice command and recognition electronics within a control moduleto control the application of power to the motor of fluid pump.

In use, doctor D may use first hand H.sub.1 both to insert infusionneedle 25 into patient P and to guide infusion needle 25 to the desiredlocation within patient P. Doctor D may use second hand H.sub.2 tooperate handheld ultrasound imager 15 so that infusion needle 25 may beobserved during its placement. If doctor D wishes to aspirate fluid fromthe patient, doctor D may step on second foot pedal 23. If doctor Dwishes to inject a fluid, such as anesthesia, through infusion needle25, doctor D may step on first foot pedal 21. If the pressure within thefluid path exceeds the threshold value at any time when first foot pedal21 or second foot pedal 23 is depressed, fluid pump 19 will shut down,stopping any injection or aspiration.

As can be appreciated, one of the benefits of system 11, as compared toconventional injection needle systems, is that system 11 does notrequire, for its operation, the participation of a plurality ofindividuals, but rather, may be operated by a single individual, such asa physician. For example, the physician may hold infusion needleassembly 13 in first hand H.sub.1 and may hold handheld ultrasoundimager 15 in second hand H.sub.2, observing the positioning of infusionneedle 25 on monitor 31. Then, to inject fluid into patient P throughinfusion needle 25, or to aspirate fluid from patient P through infusionneedle 25, the physician may merely step on first foot pedal 21 or onsecond foot pedal 23, respectively. In so doing, the physician does notneed to remove his hands from infusion needle assembly 13 or fromhandheld ultrasound imager 15.

Moreover, where, as in the present embodiment fluid pump 19 includes amechanism that automatically causes pumping to slop when the fluidpressure within the fluid path exceeds a predetermined threshold, system11 may enable one to avoid the undesirable consequences resulting fromexcessively high fluid pressures and obviates the need for one toactively monitor the fluid pressure during injection or aspiration toensure that excessively high fluid pressures are not reached.

Therefore, where system 11 is used by a physician to perform a nerveblock procedure, system 11 enables the physician to perform the nerveblock without the assistance of other individuals. This is becausesystem 11 enables the physician to control the infusion and aspirationof fluids through the infusion needle without using his hands, which aretypically required for the fine control of adjusting the needle tiplocation and for the manipulation of the position and/or controls of aneedle tip monitoring device. Moreover, system 11 can minimize nervedamage by limiting the pressure of the fluid medication to less than thethreshold at which neuronal damage to the nerve is induced.

If desired, one or more components of system 11 and, in some cases, allof the components of system 11, except possibly for handheld ultrasoundimager 15, may be disposable, single-use items. This single-use may bedesirable as it may provide a convenient way of ensuring the sterilityof system 11 in an operating room or surgery center environment.

As can be appreciated, system 11 may be modified to provide only thecapacity to inject fluid or only the capacity to aspirate fluid. If somodified, the components of system 11 pertaining to the eliminatedfunction may be omitted, and fluid pump 19 may be modified to pump fluidin only the corresponding direction.

Referring now to FIG. 2 , there is shown a perspective view, partlyschematic, of a second embodiment of a system according to the presentinvention for controllably administering fluid to a patient and/or forcontrollably withdrawing fluid from the patient, the system beingrepresented generally by reference numeral 101.

System 101 may include one or more of an infusion needle assembly 103, ahandheld ultrasound imager 105, a nerve stimulator lead 106, asyringe/pump assembly 107, a power source 109, a control device 111, afirst foot pedal 113, and a second foot pedal 115. Each of the foregoingcomponents will now be discussed further below.

Infusion needle assembly 103, which may be similar to infusion needleassembly 13, may be conventional and may include an infusion needle 117and a needle hub 119. Infusion needle 117 may be a generally tubularmember having a sharpened distal end 120 and may have a length of, forexample, approximately 25 mm to approximately 150 mm and an outerdiameter of, for example, approximately 25 gauge to approximately 18gauge, Needle hub 119 may be a generally tubular or otherwise fingergraspable member coaxially positioned around and fixed to infusionneedle 117.

Handheld ultrasound imager 105 may be similar to handhold ultrasoundimager 15 of system 11 and may be used in a similar fashion.

Nerve stimulator lead 106 may comprise a wire 121 or other electricallyconductive member having a first end inserted into needle hub 119 and incontact with infusion needle 117 and a second end coupled to anelectrically conductive connector 125. At least a portion of the lengthof wire 121 between its first and second ends may be coaxially coveredwith an electrically insulating jacket (not shown). Connector 125 may becoupled to a source of electrical current, and nerve stimulator lead 106may be used in the fashion described above to cause a body portioncontacted by infusion needle 117 to involuntarily twitch, therebyproviding a visual indicator to the physician of the location ofinfusion needle 117.

If desired, one or both of handheld ultrasound imager 105 and nervestimulator lead 106 may be omitted from system 101.

Syringe/pump assembly 107 may comprise a syringe 131 and a pump 133.Syringe 131 may be used to hold a quantity of a fluid, such as amedication (e.g., anesthesia) to be administered to a patient or to holda quantity of a fluid that has been aspirated from the patient. Syringe131 may be fluidly coupled to infusion needle assembly 103 by a lengthof tubing 135. Pump 133 may be used to expel fluid from syringe 131 orto draw fluid into syringe 131 by controlling the operation of syringe131. Referring now to FIGS. 3(a), 3(b), and 4, syringe/pump assembly 107is shown in greater detail.

Syringe/pump assembly 107 may include one or more of a syringe body 141,a syringe plunger 143, a seal 145, a housing body 147, a housing cover149, a clip 151, a motor carrier 153, a friction plate 155, a motor 157,a gear 159, a rotary actuator 161, and a knob 163. Each of the foregoingcomponents will now be discussed further below.

Syringe body 141, which is also shown separately in FIGS. 5(a) and 5(b),may be conventional and may comprise a unitary tubular member shaped todefine a generally cylindrical main portion 171 having a flange 173disposed at a proximal end thereof and having a male luer connector 175disposed at a distal end thereof. Flange 173 may be of the type that isappropriately sized and shaped to permit the forefinger and the middlefinger of an operator to be rested thereon in the conventional fashion.Male luer connector 175 may be appropriately constructed to mate with afemale luer connector (not shown) on the proximal end of a tubing 135fluidly interconnecting syringe body 141 and infusion needle assembly103 (see FIG. 2 ). Although not shown, markings may be provided on mainportion 171 to indicate the volume of fluid present within syringe body141. In the embodiment shown, syringe body 141 may be dimensioned tohold approximately 20 ml of fluid; however, syringe body 141 need not beso dimensioned and may be dimensioned to hold greater than 20 ml offluid (e.g., up to 60 ml or more) or less than 20 ml of fluid (e.g.,down to 10 ml or less). Syringe body 141 may be molded or otherwisefashioned from a rigid, transparent, medical-grade polymer or similarmaterial.

Syringe plunger 143, which is also shown separately in FIGS. 6(a) and6(b), may comprise an elongated unitary member, which may be molded orotherwise fashioned from a rigid, medical-grade polymer or similarmaterial. Syringe plunger 143 may be shaped to include a column portion181 that is generally semi-annular in transverse cross-section. A rack183, whose purpose will become apparent below, may be formed on aninterior surface of column portion 181 along at least a portion of thelength of column portion 181. An end member 185 may be provided at thedistal end of column portion 181. A distal end 186-1 of end member 185may be adapted to receive seal 145 thereover. A proximal end 186-2 ofend member 185 may be adapted to engage a circumferential rib 187 on theinterior of syringe body 141 (see FIG. 5(b)) to delimit proximalmovement of syringe plunger 143 relative to syringe body 141. A handle189 may be provided at the proximal end of column portion 181.

Seal 145, which is also shown separately in FIGS. 7(a) and 7(b), may beconventional. As noted above, seal 145 may be mounted on the distal end186-1 of syringe plunger 143 and may be appropriately dimensioned toprovide a fluid-tight seal between syringe body 141 and syringe plunger143.

Housing body 147, which is also shown separately in FIGS. 8(a) and 8(b),may be a unitary structure molded or otherwise fashioned from a suitablystorage material, such as a suitable polymer, metal or other material.Housing body 147 may be shaped to include an angled bottom wall 191, aproximal wall 193, a distal wall 195, a left wall 197, a right wall 199,and an open top. Bottom wall 191 may be provided with a plurality oftransverse openings 201, 203, 205 and 207, which may be adapted tomatingly receive corresponding structures provided on clip 151. Proximalwall 193 may be shaped to include a recess 209, which may beappropriately dimensioned for syringe plunger 143 to be slidably mountedthereacross. Distal wall 195 may also be slurped to include a recess211, which may be appropriately dimensioned for cylindrical portion 171of syringe body 141 to extend therethrough. A first internal wall 213,which may be spaced in a parallel fashion a short distance from distalwall 195, may extend upwardly from bottom wall 191 and may be joined ata first end 215 to left wall 197. A second internal wall 217 may join asecond end 219 of first internal wall 213 to distal wall 195 such thatfirst internal wall 213, second internal wall 217, left wall 197 anddistal wall 195 jointly define a compartment 219. Compartment 219 may beappropriately dimensioned to securely receive flange 173 of syringe body141. First internal wall 213 may be shaped to include a recess 221,which may be appropriately dimensioned for syringe plunger 143 to beslidably mounted thereacross. A rib 223 may extend upwardly from bottomwall 191 proximate to left wall 197 and may be appropriately sized andshaped to provide support to syringe plunger 143, which may slidethereacross. A pair of rails 225, on which motor earner 153 may beslidably mounted, may extend upwardly from bottom wall 191 and mayextend parallel to proximal wall 193 and distal wall 195. (It may benoted that only one of rails 225 can be seen in the drawings, the otherrail 225 being obscured by distal wall 195.) A transverse opening 227may be provided at the intersection of bottom wall 191 and left wall197. A transverse opening 229 may be provided in right wall 199.Openings 227 and 229 may be used to receive complementary resilient tabsformed on housing cover 149 for use in detachably coupling togetherhousing body 147 and housing cover 149. Although not shown, housing body147 may additionally include one or more openings through whichelectrical wires connected to power source 109, control device 111,first foot pedal 113, and second foot pedal 115 may be passed.

Housing cover 149 which is also shown separately in FIGS. 9(a) and 9(b)may be a unitary structure molded or otherwise fashioned from a suitablystrong material, such as a suitable polymer, metal or other material.Housing cover 149 may be shaped to include an angled top wall 241, aproximal wall 243, a distal wall 245, a left wall 247, a right wall 249,and an open bottom. Top wall 241 may be provided with a transverseopening 251, which may be adapted for the rotatable mounting of rotaryactuator 161 therewithin. Proximal wall 243 may be shaped to include arecess 253, which, like recess 209 of housing body 147, may beappropriately dimensioned for syringe plunger 143 to be slidably mountedthereacross. Distal wall 245 may be shaped to include a recess 255,which, like recess 211 of housing body 147, may be appropriatelydimensioned tor cylindrical portion 171 of syringe body 141 to extendtherethrough. A first internal wall 291, which may be spaced in aparallel fashion a short distance from distal wall 245, may extenddownwardly from top wall 241 and may be joined at a first end 263 toleft wall 247. A second internal wall 265 may join a second end 271 offirst internal wall 261 to distal wall 245 such that first internal wall261, second internal wall 265, left wall 247 and distal wall 245 jointlydefine a compartment 269. Compartment 269, like compartment 219 ofhousing body 147, may be appropriately dimensioned to securely receiveflange 173 of syringe body 141. First internal wall 261 may be shaped toinclude a recess 272, which may be appropriately dimensioned for syringeplunger 143 to be slidably mounted thereacross. A rib 273 may extenddownwardly from top wall 241 proximate to left wall 247 and may beappropriately sized and shaped to provide support to syringe plunger143, which may slide thereacross. A pair of rails 225 and 277, againstwhich motor carrier 153 may slide, may extend downwardly from top wall241 and may extend parallel to proximal wall 243 and distal wall 245.Left wall 247 may be shaped to include a resilient tab 279 having a freeend 280 that may be matingly inserted into opening 227, and right wall249 may be shaped to include a resilient tab 281 having a free end 282that may be matingly inserted into opening 229.

Clip 151, which is also shown separately in FIG. 10 , may be a unitarystructure molded or otherwise fashioned from a suitably strong material,such as a suitable polymer, metal or other material. Clip 151 may beshaped to include a block 301, which may be adapted to mate with opening201 of housing body 147. Clip 151 may be additionally shaped to includeresilient tabs 303, 305, and 307, which may be adapted to be matinglyreceived in openings 203, 205, and 207, respectively, of housing body147 so that clip 151 may be securely coupled to housing body 147. Clip151 may be further shaped to include a first transverse opening 311,which may be defined, in part, by a pair of resilient fingers 313 and315, and a second transverse opening 317, which may be defined, in part,by resilient fingers 323, 325, 327 and 329. A surgical drape worn bypatient P, a bed linen for a bed on which patient P may be positioned,or a similar item may be inserted through transverse opening 311 andfrictionally engaged, i.e., gripped, by one or both of fingers 313 and315 and/or may be inserted through transverse opening 317 andfrictionally engaged by one or more of resilient fingers 323, 325, 327,and 329. In this manner, syringe/pump assembly 107 may be immobilizedduring whatever medical procedure is to be performed.

Although housing body 147 and clip 151 are shown in the presentembodiment as being two separate pieces, it can readily be appreciatedthat body 147 and clip 151 may be formed as a single piece.

Molar carrier 153, which is also shown separately in FIGS. 11(a) and11(b), may be a unitary structure molded or otherwise fashioned from asuitably strong material, such as a suitable polymer, metal, such asbrass, or other material. Motor carrier 153 may be shaped to include atrough portion 331 and a tab portion 333. Trough portion 331, which maybe adapted to securely receive motor 157, may be shaped to include abottom wall 335, a proximal wall 337, a distal wall 339, a right sidewall 341, an open left side, and an open top. An opening 343 may beprovided in bottom wall 335 so that wires connected to power source 109,control device 111, first foot pedal 113, and second foot pedal 115 maybe passed therethrough. Proximal wall 337 and distal wall 339 may beshaped to include resilient members 342, which may function to securelyretain motor 157 within trough portion 331. Ribs 343 and 345 may beprovided along proximal wall 337 and distal wall 339, respectively. Ribs343 and 345 may be appropriately dimensioned to ride on top of rails 225of housing body 147 and beneath rails 275 and 277 of housing cover 149so that motor carrier 153 may be moved translationally between the leftand right side walls of housing body 147 and housing cover 149. Tabportion 333 may be shaped to include an opening 349 and a slot 351.Opening 349 may be used to receive a screw 350, which may be used tosecure friction plate 155 to tab portion 333. Slot 351, which may begenerally oval in shape, may be oriented at an angle (e.g.,approximately 45 degrees) relative to the longitudinal axis of motorcarrier 153. Slot 351 may be used to receive rotary actuator 161, aswill be discussed further below, so that rotation of rotary actuator 161may cause motor carrier 153 to move translationally within housing body147 and housing cover 149.

Friction plate 155, which is also shown separately in FIGS. 12(a) and12(b), may be a unitary structure molded or otherwise fashioned from asuitably strong material, such as a suitable polymer, metal or othermaterial. Friction plate 155 may be appropriately dimensioned to sit ontop of tab portion 333 of motor carrier 153. Friction plate 155 may beshaped to include an opening 361 that may be aligned with opening 349 ofmotor carrier 153 so that screw 350 may be inserted through both opening361 and opening 349 in order to couple friction plate 155 to motorcarrier 153. Friction plate 155 may also be shaped to include a slottedprojection 363, which may be tightly received within slot 351 of motorcarrier 153.

It should be understood that friction plate 155 may be eliminated ifadequate friction can be maintained between rotary actuator 161 andmotor carrier 153.

Motor 157, which is also shown separately in FIG. 13 , may be aconventional bi-directional DC motor. Motor 157 may comprise a rotatableshaft 371. Motor 157 may be appropriately dimensioned to be securelyreceived in trough portion 331 of motor carrier 153, with shaft 371extending through the open left side of motor carrier 153.

Gear 159, which is also shown separately in FIGS. 14(a) and 14(b), maybe a unitary structure molded or otherwise fashioned from a suitablystrong material, such as a suitable polymer, metal or other material.Gear 159 may be appropriately shaped to include a base portion 381 and atoothed wheel 383. Base portion 381 may include a longitudinallyextending bore 384, which may be appropriately dimensioned to securelyand coaxially receive rotatable shaft 371 so that gear 159 may becoupled to rotatable shaft 371 for rotation. Toothed wheel 383 may beappropriately dimensioned so that, when gear 159 is brought intoengagement with rack 183 of syringe plunger 143, the rotation of gear159 causes syringe plunger 143 to be moved translationally relative tosyringe body 141, resulting either in the expulsion of fluid fromsyringe body 141 or in the suctioning of fluid into syringe body 141,depending on the direction in which syringe plunger 143 is moved.

Rotary actuator 161, which is also shown separately in FIGS. 15(a) and15(b), may be a unitary structure molded or otherwise fashioned from asuitably strong material, such as a suitable polymer, metal or othermaterial. Rotary actuator 161 may be shaped to include a base portion391, a first post portion 393, and a second post portion 395. Baseportion 391 may be generally cylindrical in shape. First post portion393, which may extend upwardly from base portion 391 and which may becoaxial therewith, may be generally cylindrical in shape and may have areduced diameter as compared to base portion. First post portion 393 mayinclude a beveled area 397 proximate to its free end 399. Second postportion 395, which may extend downwardly from base portion 391 and whichmay be off-axis relative to base portion 391 and first post portion 393,may be appropriately dimensioned for engagement with slotted projection363 of friction plate 155. Consequently, as first post portion 393 isrotated, second post portion 395 causes motor carrier 153 to be movedtranslationally within housing body 147 and housing cover 149 between afirst location, at which gear 159 is engaged with rack 183, and a secondlocation, at which gear 159 is disengaged from rack 183.

Knob 163, which is also shown separately in FIGS. 16(a) and 16(b), maybe a unitary structure molded or otherwise fashioned from a suitablystrong material, such as a suitable polymer, metal or other material.Knob 163 may be shaped to include a bore 401, which may be appropriatelydimensioned to securely and coaxially receive free end 399 of rotaryactuator 161. An opening 403 may be provided in knob 163 to receive ahex socket 405 for securing knob 163 to first post portion 393 of rotaryactuator 161.

Referring back now to FIG. 2 , power source 109 may be a DC powersource, such as one or more batteries, which batteries may be disposablebatteries. Although power source 109 is shown in the present embodimentas being external to syringe/pump assembly 107, it should be understoodthat power source 109 may be incorporated into syringe/pump assembly107. Alternatively, as discussed further below, power source 109 may beincorporated into foot pedals 113 and 115.

Control device 111 may be any type of mechanism for keeping the pressurein the fluid path from exceeding a predetermined threshold. Where system101 is being used, for example, to anesthetize a nerve, the thresholdvalue may be approximately 10 psi to approximately 20 psi, preferablyapproximately 15 psi to approximately 20 psi. Such a pressure controlmechanism may operate, for example, by limiting the maximum motor torqueby voltage or current control, by using a mechanical or electromagneticclutch, by electrical current limiting the battery source, by using apressure relief valve which bleeds fluid as waste to limit the pressure,or by using a pressure sensor to cutoff power to the drive mechanism ata pressure limit. If a maximum torque specification or a currentlimiting of the battery source is employed, then, if an occlusion occursin the fluid path that causes the fluid pressure to exceed thethreshold, such a maximum torque specification or current limiting ofthe battery source simply stalls the factor and does not allow it todrive the plunger any further. Alternatively, with a pressure reliefvalve, the fluid flow is simply diverted from the fluid path, keepingthe pressure below the threshold. With a pressure sensor, the effect isto simply cutoff the power source to the motor.

Referring now to FIG. 17 , there is shown a simplified schematicrepresentation of a first exemplary embodiment of control device 111.(For simplicity and ease of understanding, the first exemplaryembodiment of control device 111 is shown in FIG. 17 as part of system101. Certain elements of system 101, such as handheld ultrasound imager105, nerve stimulator lead 106, first foot pedal 113, and second footpedal 115, are not shown in FIG. 17 .) As shown in FIG. 17 , the firstexemplary embodiment of control device 111 may be in the form of amaximum torque (pressure) limiter that may comprise a resistor 425. Theresistance of resistor 425 may be selected so as to cause motor 157 tostop or to stall when the fluid pressure its the fluid path exceeds apredetermined threshold pressure. Where, for example, system 11 isintended to be used to administer regional anesthesia, such a thresholdpressure may be approximately 15 psi. The necessary magnitude ofresistance provided by resistor 425 may depend on one or more factors,such as, but not limited to, the type of motor being used and the sizeof syringe being used.

Referring now to FIG. 18 , there is schematically shown an experimentalset-up that was used to measure the pressure generated by a smallelectric motor used in a prototype of syringe/pump assembly 107 fordriving a 20 mL syringe whose output was occluded, the experimentalset-up being represented generally by reference numeral 428.

Set-up 428 comprises syringe/pump assembly 107. Assembly 107 iselectrically connected to each of power source 109 and control device111. The output of syringe/pump assembly 107 is coupled to an input end429 of a length of tubing 430. An occlusion cap 423 is mounted on anoutput end 431 of tubing 430, and a pressure sensor 433 is positioned atan intermediate point within tubing 430. As can be seen in FIG. 19 , asthe resistance increased from about 10 ohm to about 40 ohm, the maximumpressure decreased from about 18 psi to about 7 psi. In particular, an18-ohm resistor in series with moon 157 limited the torque and resultedin a maximum pressure of just under 15 psi, which is a desirable result.FIG. 20 shows the flow rates for various needle types (i.e., a 22-gaugeneedle, a 20-gauge needle, an 18-gauge needle, and an occluded needle)using set-up 428 with an 18-ohm resistor for control device 111 (andreplacing occlusion cap 432 with the various needles). The resultingflow rates for the non-occluded needles varied from about 0.13 mL/see toabout 0.46 mL/sec.

Referring now to FIG. 21 , there is shown a simplified schematicrepresentation of a second exemplary embodiment of control device 111.(For simplicity and ease of understanding, the second exemplaryembodiment of control device 111 is shown in FIG. 21 as part of system101. Certain elements of system 101, such as handheld ultrasound imager105, nerve stimulator lead 106, first foot pedal 113, and second tootpedal 115, are not shown in FIG. 21 .) In order to distinguish thesecond exemplary embodiment of control device 111, which is shown inFIG. 21 , from the first exemplary embodiment of control device 111,which shown in FIG. 17 , the second exemplary embodiment of controldevice 111 is represented generally in FIG. 21 by reference numeral111′. As shown in FIG. 21 , control device 111′ may be in the form of amaximum torque (pressure) limiter that may comprise a current sensingcircuit (or current sensor) 435, a resistor 437, and a shutoff switch439.

Referring now so FIG. 22 , there is shown a simplified schematicrepresentation of a third exemplary embodiment of control device 111.(For simplicity and ease of understanding, the third exemplaryembodiment of control device 111 is shown in FIG. 22 as part of system101. Certain elements of system 101, such as handheld ultrasound imager105, nerve stimulator lead 106, first foot pedal 113, and second footpedal 115, are not shown in FIG. 22 .) In order to distinguish the thirdexemplary embodiment of control device 111, which is shown in FIG. 22 ,from the first exemplary embodiment of control device 111, which shownin FIG. 17 , the third exemplary embodiment of control device 111 isrepresented generally in FIG. 22 by reference numeral 111″. As shown inFIG. 22 , control device 111″ may be in the form of a maximum torque(pressure) limiter that may comprise a fluid path pressure sensor 445and a shutoff switch 447.

Referring back now to FIG. 2 , although control device 111 is shown inthe present embodiment as being external to syringe/pump assembly 107,it should be understood that control device 111 may be incorporated intosyringe/pump assembly 107. Alternatively, control device 111 may beincorporated into foot pedals 113 and 115. In the present embodiment,control device 111 may be electrically coupled to motor 157 (see FIG. 3b ) by wires 482 and 484, which may be coupled to one another by matingconnectors 486 and 488. Power source 109 may be coupled to controldevice 111 by a wire 451.

First foot pedal 113, which may be conventional, may be electricallycoupled by a wire 481 to control device 111, and second foot pedal 115,which may be conventional may be electrically coupled by a wire 485 tocontrol device 111. System 101 may be configured so that, when firstfoot pedal 113 is depressed, motor 157 is operated in injection-mode,and so that, when second foot pedal 115 is depressed, motor 157 isoperated in aspiration-mode. Alternatively, system 101 may be configuredso that, when first foot pedal 113 is depressed, motor 157 is operatedin aspiration-mode, and so that, when second foot pedal 115 isdepressed, motor 157 is operated in injection-mode. First foot pedal 113and second foot pedal 115 may be distinguishable from one another insuch a way as to indicate which foot pedal may be used for aspirationand which foot pedal may be used for infusion. For example, the footpedals may be prominently labeled with the words like “ASPIRATE” and“INFUSE” and/or may be decorated with icons that convey their respectivefunctions. In addition or alternatively, the foot pedals may be coloreddifferently, such as blue or green for infusion and yellow foraspiration.

As can readily be appreciated, although foot pedals 113 and 115 areshown in FIG. 2 being coupled to syringe/pump assembly 107 by wires,such wires may be replaced by any wireless means including, but notlimited to, using Bluetooth communications to connect foot pedals 113and 115 to fluid pump 133 or using voice command and recognitionelectronics within a control module to control the application of powerfront power source 109 to motor 157 of fluid pump 133.

If desired, one or more components of system 101 and, in fact,preferably all of the components of system 101, except possibly forhandheld ultrasound imager 15, may be disposable, single-use items. Thissingle-use feature may be desirable as it may provide a convenient wayof ensuring the sterility of system 101 in an operating room or surgerycenter environment.

To use system 101 to inject fluid into a patient, syringe/pump assembly107 may initially be arranged so that toothed wheel 383 of gear 159 isdisengaged from rack 183 of syringe plunger 143. Such an arrangementenables the physician to manually fill syringe 131 with the desiredfluid. The physician may then prime tubing 135 either manually, beforeturning rotary actuator 161 to cause toothed wheel 383 to engage rack183, or by turning rotary actuator 161 to cause toothed wheel 383 toengage rack 183 and then by depressing the appropriate foot pedal tocause toothed wheel 383 to drive syringe plunger 143 in such a way as tocause sufficient fluid to be expelled from syringe 131 to prime.Additional depression of said foot pedal when infusion needle 117 isplaced in the patient P causes fluid to be injected into the patient.If, at any time during the procedure, the physician wishes to manuallycontrol syringe 131, pump 133 can be disengaged from syringe 131 byturning rotary actuator 161 to disengage toothed wheel 383 from rack183. If aspiration of fluid front the patient P is desired, this may beaccomplished by depressing the other foot pedal, causing toothed wheel383 to move rack 183 in the opposite direction. If, while gear 383 isengaged with rack 183 and either first foot pedal 113 or second footpedal 115 is depressed, the pressure in the fluid path exceeds thepredetermined threshold, control device 111 causes gear 383 to stopdriving the movement of syringe plunger 143.

System 101 may be used to deliver fluid at a desired flow rate, such asup to 1 ml/see, without having the pressure of the fluid in the fluidpath exceed a desired threshold, such as about 15 psi. In a preferredembodiment, syringe plunger 143 may be driven at such a speed thatapproximately 0.5 milliliter of fluid per sec is dispensed front syringe131. Since physicians use a wide range of needle diameters, for example,from 16 G up to 27 G and a wide range of needle lengths, for example,from 25 millimeters to 150 millimeters, the flow rates of the fluid mayrange depending on the pump, syringe and needle type selected and mayvary, for example, from about 0.01 milliliters/sec to about 0.5millimeters/sec.

Referring now to FIG. 23 , there is shown a partly exploded perspectiveview of an alternate foot pedal for use in system 101, said alternatefoot pedal being constructed according to the present invention andbeing represented generally by reference numeral 501. Foot pedal 501 maybe used in place of first foot pedal 113 or may be used in place ofsecond foot pedal 115; alternatively, a pair of foot pedals 501 may beused in place of foot pedals 113 and 115.

Foot pedal 501 may comprise a bottom 503, a firstelectrically-conductive element 505, a pair of batteries 507-1 and507-2, a top 509, and a second electrically-conductive element 510. Eachof the foregoing components will now be discussed further below.

Bottom 503 may be a unitary structure molded or otherwise fashioned froma suitable material, which may be an electrically non-conductivematerial, such as an electrically non-conductive polymer or the like.Bottom 503 may be shaped to include a base portion 511, which may begenerally planar, a battery holder 513, which may be seated on top ofbase portion 511 proximate to a first end 512-1 of base portion 511, anda resilient member 514, which may be biased upwardly and which may bedisposed proximate to a second end 512-2 of base portion 511. Instead ofmaking battery holder 513 integral with the remainder of bottom 503,battery holder 513 may be made separately from bottom 503 and then maybe mounted on bottom 503 using an adhesive or other suitable mountingmeans.

First electrically-conductive element 505 may be an elongated unitarystructure made of a suitable, electrically-conductive material, such asa metal. First electrically-conductive element 505 may comprise a firstend 515. First end 515 may be appropriately shaped to be received withinbattery holder 513 and may be adapted to make electrical contact withbatteries 507-1 and 507-2, which may be seated on first end 515. Theremainder of first electrically-conductive element 505 may be mounted ontop of base portion 511 of bottom 503 and may be shaped to include acontact 517.

Batteries 507-1 and 507-2, which may be conventional batteries and, morespecifically, may be conventional disposable batteries, may be seated ontop of first end of first electrically-conductive element 505 withinbattery holder 513. Although two batteries 507-1 and 507-2 are shown inthe present embodiment, there could be as few as one battery or as manyas three or more batteries.

Top 509 may be a unitary structure molded or otherwise fashioned from asuitable material, which may be an electrically non-conductive material,such as an electrically non-conductive polymer or the like. Top 509 maybe shaped to include a base portion 521 and a tab 523. Tab 523, whichmay be positioned over and in contact with resilient member 514 ofbottom 503, may be adapted for hinged movement relative to base portion521. In this manner, tab 523 may be pivoted downwardly, against theforce of resilient member 514, when an operator applies sufficientdownward force to tab 523.

Second electrically-conductive element 510, which may be made of asuitable, electrically-conductive element, such as a metal, may besecured to the bottom of tab 523 at an appropriate location so that,when tab 523 is pivoted downwardly, a contact 525 provided on secondelectrically-conductive element 510 may make contact with contact 517 offirst electrically-conductive element 505. Secondelectrically-conductive element 510 may be coupled to wire 481 (if footpedal 501 is used in place of first foot pedal 113) or to wire 485 (iffoot pedal 501 is used in place of second foot pedal 115).

As can be appreciated, because foot pedal 501 includes a power source,the need for power source 109 is obviated when foot pedals 113 and 115are replaced with a pair of foot pedals 501.

Foot pedal 591 may be a disposable, single-use item.

Referring now to FIG. 24 , there is shown a perspective view of a kitconstructed according to the present invention, the kit beingrepresented generally by reference numeral 551.

Kit 551 may comprise a syringe/pump assembly 553, which may be identicalto syringe/pump assembly 107. Syringe/pump assembly 553 may be packagedwithin an inner container 555 in preferably a sealed, sterile condition.Inner container 555 may, in turn, be packaged within an outer container557 of blister packaging. A first foot pedal 559 and a second foot pedal561, both of which may be identical to foot pedal 501, may be integratedinto and form a part of outer container 557. Although not shown in FIG.24 , kit 551 may also include the wire for each of foot pedals 559 and561. Each such wire may be connected to its respective foot pedal andmay be stored within the space outside of inner container 555 but withinouter container 557. In addition, kit 551 may further include the wiresfor syringe/pump assembly 553, which wires may be stored within innercontainer 555.

Kit 551 may be a disposable, single-use item.

Referring now to FIGS. 25(a) and 25(b), there are shown perspective andpartly exploded perspective views, respectively, of a foot pedalassembly for use in system 101, said foot pedal assembly beingconstructed according to the present invention and being representedgenerally by reference numeral 601. Foot pedal assembly 601, which maybe regarded as effectively having two independently-operable pedalportions, may be used in place of both first foot pedal 113 and secondfoot pedal 115.

Foot pedal assembly 601 may comprise a plurality of batteries 603, abattery container 605, a pair of resiliently-compressible tubes 607-1and 607-2, and a pair of resiliently-compressible circuit rolls 609-1and 609-2. Each of the foregoing components will now be discussedfurther below.

Batteries 603 may be conventional batteries and, more specifically, maybe conventional disposable AA batteries. Although three batteries 603are shown in the present embodiment, there could be as few as one or twobatteries or as many as four or more batteries.

Battery container 605 may be appropriately dimensioned to hold batteries603 in a series configuration. In addition, battery container 605 mayalso be appropriately dimensioned to be coaxially inserted into adjacentends of resiliently-compressible tubes 607-1 and 607-2 so as tophysically couple resiliently-compressible tubes 607-1 and 607-2 in asecure manner. Barbs 611 may be provided on the exterior of batterycontainer 605 so enhance the interference fit between battery container605 and resiliently-compressible tubes 607-1 and 607-2.

Resiliently-compressible tubes 607-1 and 607-2 may be generallyidentical to one another in size, shape and construction but may bemarked and/or colored differently to facilitate their beingdifferentiated by an operator. Resiliently-compressible tubes 607-1 and607-2 may be molded or otherwise fashioned from blown polyethylene or asimilarly suitable material that quickly returns to its original shapeafter being radially compressed.

Resiliently-compressible circuit rolls 609-1 and 609-2, which may becoaxially disposed within appropriately dimensioned voids 616-1 and616-2 of resiliently-compressible tubes 607-1 and 607-2, respectively,may be identical to one another; accordingly, the comments belowpertaining to roll 609-1 may be applicable to roll 609-2. Roll 609-1,which is also shown separately in FIGS. 26(a) and 26(b), may comprise asheet of electrically con-conductive material 621, such as MYLARbiaxally-oriented polyethylene terephthalate or a similarly suitablematerial. A pair of conductive elements 623 and 625, each of which maycomprise, for example, a conductive ink, may be arranged on sheet 621.Conductive element 623 may be coupled to a cable 627, and conductiveelement 625 may be coupled to a cable 629. Conductive elements 623 and625 may be appropriately positioned on sheet 621 so that radialcompression of roll 609-1, such as when an operator steps onresiliently-compressible tube 607-1, causes conductive elements 623 and625 to come into contact with one another. Consequently, by stepping onresiliently-compressible tube 607-1, one may close the switch defined byroll 609-1, and by stepping on resiliently-compressible tube 607-2, onemay close the switch defined by roll 609-2.

Foot pedal assembly 601 may further comprise plugs 631 and 633. Plug 631may be used to plug the outside end of void 616-1, and plug 633 may beused to plug the outside end of void 616-2.

Foot pedal assembly 601 may further comprise a cable 635, which may beconnected at one end to a connector 637 and which may be coupled at itsopposite end to each of circuit rolls 609-1 and 609-2.

As can be appreciated, because foot pedal assembly 601 includes a powersource, the need for power source 109 is obviated when foot pedals 113and 115 are replaced with foot pedal assembly 601.

Foot pedal assembly 601 may be a disposable, single-use item.

Referring now to FIG. 27 , there is shown a perspective view, partlyschematic, of a third embodiment of a system according to the presentinvention for controllably administering fluid so a patient and/or forcontrollably withdrawing fluid from the patient, the system beingrepresented generally by reference numeral 701.

System 701 may include one or more of an infusion needle assembly 703, ahandheld ultrasound imager 705, a nerve stimulator lead 706, a fluidreceptacle 707, a peristaltic pump 709, and a foot pedal assembly 713.Each of the foregoing components will now be discussed further below.

Infusion needle assembly 703, which may be similar to infusion needleassembly 13, may be conventional and may include an infusion needle 717and a needle hub 719. Infusion needle 717 may be a generally tubular orotherwise finger graspable member having a sharpened distal end 720 andmay have a length of, for example, approximately 25 mm to approximately150 mm and an outer diameter of, for example, approximately 25 gauge toapproximately 18 gauge. Needle hub 719 may be a generally tabular membercoaxially positioned around and fixed to infusion needle 717.

Handheld ultrasound imager 705 may be similar to handheld ultrasoundimager 15 of system 11 and may be used in a similar fashion.

Nerve stimulator lead 706 may be similar to nerve stimulator lead 106 ofsystem 101 and may be used in a similar fashion.

If desired, one or both of handheld ultrasound imager 705 and servestimulator lead 706 may be omitted from system 701.

Fluid receptacle 707 may comprise a conventional syringe or other fluidreceptacle, such as, but not limited to, an intravenous fluid bag.

Peristaltic pump 709, which may be used to pump fluid from fluidreceptacle 707 to infusion needle 717 or to pump fluid from infusionneedle 717 to fluid receptacle 707, may be fluidly coupled to fluidreceptacle 707 by a first length of tubing 721 and may be fluidlycoupled to infusion needle assembly 703 by a second length of tubing723. Referring now to FIGS. 28, 29, 30 (a) and 30(b), peristaltic pump709 is shown in greater detail.

Pump 709 may include one or more of a housing 741, a motor 743, a motormagnet 745, an upper magnet washer 747, a tab washer 749, a roller 751,a silicone tube 753, a male luer 755, a female luer 757, a knob 759, atube stop 761, and a cable strain relief 763. Each of the foregoingcomponents will now be discussed further below.

Housing 741 may comprise a motor cover 765. Motor cover 765, which isalso shown separately in FIGS. 31(a) and 31(b), may be a unitarystructure molded or otherwise fashioned from a suitably strong material,such as a suitable polymer, metal or other material. Motor cover 765 maycomprise a tubular portion 767 and a tab portion 769. Tubular portion767 may include a first end 771, which may be open, a second end 773,which may be closed, except for a small opening 775, and a side wall777, which may be generally D-shaped in transverse cross section.Opening 775 may be used to receive cable strain relief 763, which, inturn, may be used to receive cable 897. A pair of resilient fingers 779may extend generally longitudinally from second end 773 on oppositesides of opening 775. Fingers 779 may be used to securely receive motor743. Tab portion 769 may be shaped to include a cloth grabber similar tothose of clip 151 of assembly, the cloth grabber comprising an opening781 defined at least in part by a pair of resilient fingers 783 and 785.

Housing 741 may further comprise a housing body 787. Housing body 787,which is also shown separately in FIGS. 32(a) and 32(b), may be aunitary structure molded or otherwise fashioned from a suitably strongmaterial, such as a suitable polymer, metal or other material. Housingbody 787 may be shaped to include an opening 789, which may be adaptedto receive motor magnet 745, tab washer 749, upper magnet washer 747,and silicone tube 753. Housing body 787 may also be shaped to include aslot 791, which may be adapted to receive tube stop 761 in such a waythat tube stop 761 may be slidably adjustable within slot 791. Housingbody 787 may additionally be shaped to include a pair of grooves 793 and795, which may be adapted to receive opposing ends of silicone tube 753.Housing body 787 may further be shaped to include a first compartment797, which may be adapted to receive female luer 757, and a secondcompartment 799, which may be adapted to receive male luer 755.

Housing 741 may further comprise a housing cover 801. Housing cover 801,which is also shown separately in FIGS. 33(a) and 33(b), may be aunitary structure molded or otherwise fashioned from a suitably strongmaterial such as a suitable polymer, metal or other material. Housingcover 801, which may be shaped to mate with housing body 787, mayinclude a first opening 803, which may be adapted to coaxially receive ashaft 805 of knob 759 in such a way that shaft 805 may be freelyrotatable within opening 803. Housing cover 801 may also include asecond opening 807, which may be adapted to receive tube stop 761 insuch a way that tube stop 761 may be slidably adjustable within secondopening 807. Housing cover 801 may additionally be shaped to include apair of grooves 809 and 811, which may be adapted to receive opposingends of silicone tube 753. Housing cover 801 may further be shaped toinclude a first compartment 813, which may be adapted to receive femaleluer 757, and a second compartment 815, which may be adapted to receivemale luer 755.

Motor 743, which is also shown separately in FIG. 34 , may be aconventional bi-directional DC motor. Motor 743 may comprise a rotatableshaft 817.

Motor magnet 745, which is also shown separately in FIGS. 35(a) and35(b), may be positioned within opening 789 of housing body 787 and maybe shaped to comprise a base 819 and a shaft 821, wherein shaft 821 mayextend upwardly from base 819. Shaft 821 may include a cavity 823, whichmay be appropriately dimensioned to receive rotatable shaft 817 of motor743 in such a way that shaft 821 may be mechanically coupled forrotation to rotatable shaft 817 of motor 743.

Upper magnet washer 747, which is also shown separately in FIGS. 36(a)and 36(b), may be positioned within opening 789 of housing body 787 andmay be shaped to include a base 831. Base 831 may be shaped to include abore 832 adapted to receive shaft 821 of motor magnet 745. A firstprojection 833 may extend upwardly coaxially from base 831, and a secondprojection 835 may extend upwardly off-axis from base 831. A thirdprojection 837 may extend upwardly coaxially from first projection 833.A bore 839 may be provided in third projection 837. Bore 839 may beappropriately dimensioned to receive shaft 805 of knob 759 in such a waythat third projection 837 may be mechanically coupled for rotation toshaft 805 of knob 759. In this manner, as will be discussed furtherbelow, manual rotation of knob 759 may be used to effect the rotation ofupper magnet washer 747, for example, to align second projection 835with tube stop 761.

Tab washer 749 may be positioned between motor magnet 745 and uppermagnet washer 747, with tab washer 749 having an opening 841 throughwhich shaft 821 of motor magnet 745 may be coaxially inserted. Thecombination of motor magnet 745, upper magnet washer 747, and tab washer749 may act as a magnetic clutch, wherein upper magnet washer 747becomes decoupled from rotation to motor magnet 745 when the pressure inthe fluid path exceeds a predetermined threshold.

As can readily be appreciated, pump 709 may be modified to replace themagnetic clutch described above with a mechanical clutch which slips ata predetermined torque to limit the forces delivered to the pumpingmechanism. Alternatively, a current limiter may be placed between thebattery and the motor to limit the torque delivered, or a pressure limitswitch may be provided in the fluid path to cutoff the electric power tothe motor, or a pressure relief valve may be provided to relieve thepressure by dumping the fluid from the fluid path.

Roller 751, which is also shown separately in FIG. 37 , may be mountedcoaxially over second projection 835 of upper magnet washer 747. Roller751 may be appropriately dimensioned to engage silicone tube 753sufficiently to pinch shut silicone tube 753. In this manner, as uppermagnet washer 747 rotates, roller 751 may serve to force fluid along thelongitudinal axis of silicone tube 753.

Silicone tube 753, which is also shown separately in FIG. 38 , may havea first end 851, a second end 853, and a looped portion 855. First end851 may be positioned in groove 793 of housing body 787 and in groove809 of housing cover 801. Second end 853 may be positioned in groove 795of housing body 787 and in groove 811 of housing cover 801. Loopedportion 855 may be seated on base 831 of upper magnet washer 747 and maybe wrapped around first projection 833 and second projection 835 ofupper magnet washer 747.

Male luer 755, which is also shown separately in FIGS. 39(a) and 39(b),may be a generally tubular unitary structure molded or otherwisefashioned from a suitably strong material, such as a suitable polymer,metal or other material. Male luer 755 may be shaped to include a firstend 861 and a second end 863. First end 861 may be adapted for insertioninto second end 853 of silicone tube 753. Second end 863 may be adaptedto be mated with a female connector (not shown) on second tubing 723(see FIG. 27 ).

Female luer 757, which is also shown separately in FIGS. 40(a) and40(b), may be a generally tubular unitary structure molded or otherwisefashioned from a suitably strong material, such as a suitable polymer,metal or other material. Female luer 757 may be shaped to include afirst end 865 and a second end 867. First end 865 may be adapted forinsertion into first second end 851 of silicone tube 753. Second end 867may be adapted to be mated with a male connector (not shown) on firsttubing 721 (see FIG. 27 ).

Knob 759, which is also shown separately in FIG. 41 , may be a unitarystructure molded or otherwise fashioned from a suitably strong material,such as a suitable polymer, metal or other material. Knob 759 maycomprise a head 871 and shaft 805. Shaft 905 may be appropriatelydimensioned to for insertion through opening 803 in housing cover 801and into engagement with bore 839 of upper magnet washer 747.

Tube stop 761, which is also shown separately in FIGS. 42(a) and 42(b),may be a unitary structure molded or otherwise fashioned from a suitablystrong material, such as a suitable polymer, metal or other material.Tube stop 761 may be shaped to have a comparatively greater thickness ata first end 881 and a comparatively lesser thickness at a second end893. A reason for the non-uniform thickness of tube stop 761 is setforth below.

A premise for the inclusion of pump 709 in system 701 is to allow fluidto be pumped automatically without needing so handle a syringe in thetraditional way. However, under certain conditions, it may be essentialor desirable to pump the fluid manually. Consequently, pump 709 shouldbe designed to allow the free flow of fluid through pump 709 undersyringe control and to allow the same syringe dexterity and backpressure sensitivity for the doctor.

For this reason, pump 709 may be adjustable between a manual mode and anautomatic mode. An automatic mode may be understood to mean that theelectric motor moves the rotor and pumps fluid with no hands on thesyringe. There are several reasons why manual mode may be required ordesired: (1) if the motor fails part-way through drug administrationinfusion or aspiration; (2) if the doctor chooses to fill the syringemanually with the pump attached to the output port of the syringe; (3)if the doctor chooses to prime the pump housing, tubing and needlemanually, instead of automatically with the motor.

To allow pump 709 have a manual mode capability, pump 709 includes anadjustable back plate, i.e., tube stop 761, where the tubingcrosses-over or loops onto itself. The thickness of tube stop 761 isdesigned so that it can achieve two “states”—tube compression or nocompression at a particular point in the tube housing. To this end, tubestop 761 has one thick end and one thin end. The profile between the twoends is a ramp which allows smooth transition from one state to theother as tube stop 761 is moved from its compressing position to anon-compressing position.

With the motor turned off, roller 751 may be rotated manually to thetube cross-over point by the use of knob 759. Positioning roller 751manually ensures that roller 751 is aligned with tube stop 761. This isbecause the motor could stop anywhere in its 360 degree rotation path.When roller 751 is aligned and tube stop 761 is slid into anon-compressing condition by the operator, fluid can pass throughsilicone tube 753 freely with no restriction. Reinstating automatic(motor-powered mode) is as simple as sliding tube stop 761 back into acompressing position.

As can be appreciated, although pump 709 is described herein as being ofthe type comprising a single roller 751, pump 709 may be modified toinclude a plurality of rollers

Referring back now to FIG. 27 , foot pedal assembly 713, which may beidentical to foot pedal assembly 601, may be electrically coupled by acable 891 to a connector 893. Connector 893, in turn, may be connectedto a connector 895, which, in turn, may be electrically coupled to motor743 (see FIG. 29 ) by a cable 897.

It should be recognized that foot pedal assembly 713 may be replaced bya pair of conventional foot pedals or by a pair of foot pedals similarto foot pedal 501.

If desired, one or more components of system 701, and in fact,preferably all of the components of system 701, except possibly forhandheld ultrasound imager 705, may be disposable, single-use items.This single-use feature may be desirable as it may provide a convenientway of ensuring the sterility of system 701 in an operating room orsurgery center environment.

Referring now to FIG. 43 , there is shown a fourth embodiment of asystem according to the present invention for controllably administeringfluid to a patient and/or for controllably withdrawing fluid from thepatient, the system being represented generally by reference numeral901.

System 901 may comprise one or more of a syringe 903, an infusion needleassembly 905, extension tubing 907, a pump 909, a first foot pedal 911and a second foot pedal 913. Although not shown, system 901 may alsocomprise one or both of a handheld ultrasound imager and a nervestimulator lead.

Syringe 903, infusion needle assembly 905 and extension tubing 907 maybe conventional. First foot pedal 911 and second foot pedal 913 may takethe form of any of the conventional or novel foot pedals or foot pedalassemblies discussed herein.

Pump 909 may comprise a female luer connector (not shown) that may beconnected directly to the male luer connector 917 of syringe 903. Pump909 may further comprise three solenoids 921, 923 and 925 that control adistal valve diaphragm 927, a pump diaphragm 929, and a proximal valvediaphragm 931, respectively. When powered, the microcontroller 933 hasthree states: non-pumping, infusing, and aspirating. In the non-pumpingstate, the diaphragms are in the normally open position so there is aclear fluid path from the proximal end 941 of pump 909 to the distal end943 of pump 909. In either the infusion or aspiration states, solenoids921, 923, and 925 are each sequenced in time to aspirate from one end ofthe pump 909 with one of valves 927 and 931 open and the other of valves927 and 931 closed and with the pump diaphragm 929 pulled to the upposition against the force of the compression spring 945. In the nexttime sequence, the valves 927 and 931 are reversed from open to closedand closed to open, and the pump diaphragm 929 is allowed to be drivenby the spring 945. The fluid pressure limit is set by the product of thedisplacement of the spring 945 and the spring constant divided by thearea of the diaphragm 929. The flow rate will be determined by the fixedrate of the time sequencing and the pressure in the fluid path. Thehigher the time sequencing, the higher the flow rate. The higher thepressure, the lower the flow rate. In the event of an occlusion in thefluid path, the fluid pressure will build up, which will reduce thelinear displacement of the pump diaphragm 929 until it ultimately has nodisplacement as the maximum allowed pressure, thereby reducing the flowrate to zero. This pump has a maximum pressure allowable in the fluidpath and a variable flow rate which is a function of the pressure in thefluid path. By comparison, most traditional syringe pumps havecontrolled flow rates with a maximum pressure limit threshold.

Referring now to FIG. 44 , there is shown a fifth embodiment of a systemaccording to the present invention for controllable administering fluidto a patient and/or for controllably withdrawing fluid from the patient,the system being represented generally by reference number 951.

System 951 may comprise one or more of a syringe 953, an infusion needleassembly 955, extension tubing 957, a pump 959, a first foot pedal 961and a second foot pedal 963. Although not shown, system 951 may alsocomprise one or both of a handheld ultrasound imager and a nervestimulator lead.

Infusion needle assembly 955 and extension tubing 957 may beconventional. First foot pedal 961 and second foot pedal 963 may takethe form of any of the conventional or novel foot pedals or foot pedalassemblies discussed herein.

Pump 959 may be a pneumatic pump that pumps at a pressure less than thethreshold pressure one wishes not to exceed, e.g., 15 psi for nerveblock procedures. An end cap 965 may be positioned at the proximalflange 967 of syringe 953 to create a sealed cavity between end cap 965and distal end of plunger 969. A pneumatic port 971 may be provided inend cap 965, which accepts either positive pneumatic gauge pressure toinfuse equivalent to the pressure limit imposed on the pneumatic pump959 with foot pedals 961 and 963 by driving plunger 969 distally oraccepts negative pneumatic gauge pressure to aspirate by driving plunger969 proximally.

Referring now to FIG. 45 , there is shown a perspective view, partlyschematic, of a sixth embodiment of a system according to the presentinvention for controllably administering fluid to a patient and/or forcontrollably withdrawing fluid from the patient, the system beingrepresented generally by reference numeral 1001.

System 1001 may include one or more of an infusion needle assembly 1003,a handheld ultrasound imager 1005, a nerve stimulator lead 1006, asyringe/pump assembly 1007, and a foot pedal assembly 1009. Each of theforegoing components will now be discussed further below.

Infusion needle assembly 1003, which may be similar to infusion needleassembly 13, may be conventional and may include an infusion needle 1017and a needle hub 1019. Infusion needle 1017 may be a generally tubularmember having a sharpened distal end 1020 and may have a length of, forexample, approximately 25 mm to approximately 150 mm and an outerdiameter of, for example, approximately 25 gauge to approximately 18gauge. Needle hub 1019 may be a generally tubular or otherwise fingergraspable member coaxially positioned around and fixed to infusionneedle 1017.

Handheld ultrasound imager 1005 may be similar so handheld ultrasoundimager 15 of system 11 and may be used in a similar fashion.

Nerve stimulator lead 1006 may comprise a wire 1021 or otherelectrically conductive member having a first end inserted into needlehub 1019 and in contact with infusion needle 1017 and a second endcoupled to an electrically conductive connector 1025. At least a portionof the length of wire 1021 between its first and second ends may becoaxially covered with an electrically insulating jacket (not shown).Connector 1025 may be coupled to a source of electrical current, andnerve stimulator lead 1006 may be used in the fashion described above tocause a body portion contacted by infusion needle 1017 to involuntarilytwitch, thereby providing a visual indicator to the physician of thelocation of infusion needle 1017.

If desired, one or both of handheld ultrasound imager 1005 and nervestimulator lead 1006 may be omitted from system 1001.

Syringe/pump assembly 1007, which is also shown separately in FIGS.46(a) through 46(c), may comprise a syringe 1031, a pump 1033, and anadaptor 1034. Each of the foregoing components will now be discussed infurther detail.

Syringe 1031 may be used to hold a quantity of a fluid, such as amedication (e.g., anesthesia) to be administered to a patient or may beused to hold a quantity of a fluid that has been aspirated from thepatient. Syringe 1031 may comprise a syringe body 1041, a syringeplunger 1043 and a seal 1045.

Syringe body 1041, which may be similar to syringe body 141, maycomprise a unitary tubular member shaped to define a generallycylindrical main portion 1071 having a flange 1073 disposed at aproximal end thereof and having a male luer connector 1075 disposed at adistal end thereof. Male luer connector 1075 may be appropriatelyconstructed to mate with a female luer connector (not shown) on theproximal end of a length of tubing 1035 that may be used to fluidlyinterconnect syringe body 1041 and infusion needle assembly 1003.Markings 1077 may be provided on main portion 1071 of syringe body 1041to indicate the volume of fluid present within syringe body 1041. In theembodiment shown, syringe body 1041 may be dimensioned to holdapproximately 20 ml of fluid; however, syringe body 1041 need not be sodimensioned and may be dimensioned to hold greater than 20 ml of fluid(e.g., up to 60 ml or more) or less than 20 ml of fluid (e.g., down to10 ml or leas). Syringe body 1041 may be molded or otherwise fashionedfrom a rigid, transparent, medical-grade polymer or similar material.

Syringe plunger 1043, which is also shown separately in FIG. 47 andwhich may be similar to syringe plunger 143, may comprise an elongatedunitary member, which may be molded or otherwise fashioned from a rigid,medical-grade polymer or similar material. Syringe plunger 1043 may beshaped to include a column portion 1081 that is generally semi-annularin transverse cross-section. A rack 1083, whose purpose will becomeapparent below, may be formed on an interior surface of column portion1081 along at least a portion of the length of column portion 1081. Anend member, end cap or collar 1085 may be provided at the distal end ofcolumn portion 1081. A distal end 1086-1 of end member 1085 may beadapted to receive seal 1045 thereover. A proximal end 1086-2 of endmember 1085 may be adapted to engage a circumferential rib (not shown)on the interior of syringe body 1041 to delimit proximal movement ofsyringe plunger 1043 relative to syringe body 1041. A handle 1089 may beprovided at the proximal end of column portion 1081.

Seal 1045, which may be similar to seal 145, may be conventional. Asnoted above, seal 1045 may be mounted on the distal end 1086-1 ofsyringe plunger 1043 and may be appropriately dimensioned to provide afluid-tight seal between syringe body 1041 and syringe plunger 1043.

Pump 1033, which may be used to expel fluid from syringe 1031 or to drawfluid into syringe 1031 by appropriately driving translational movementof syringe plunger 1043 relative to syringe body 1041, may comprise ahousing body 1047, a housing cover 1049, a power source 1051, a controldevice 1053, a locking clip 1055, a motor 1057, and a gear 1059. Each ofthe foregoing components will now be discussed further below.

Housing body 1047, which is also shown separately in FIGS. 48(a) through48(e) may be a unitary structure molded or otherwise fashioned from asuitably strong material, such as a suitable polymer, metal or othermaterial. Housing body 1047, which may take the form of a generallyrectangular trough, may be shaped to include a bottom wall 1091, a firstside wall 1093, a second side wall 1095, a first end wall 1097, a secondend wall 1099, and an open top. A plurality of wall, embossments andother structural features may extend upwardly from or otherwise beprovided in bottom wall 1091 of housing body 1047. As an example of onesuch feature, a plurality of transverse openings 1101, 1103, 1105, and1107 may be provided in bottom wall 1091 proximate to its four corners.As an example of another such feature, a plurality of hollow posts 1111,1113, 1115, and 1117, which hollow posts may be aligned with transverseopenings 1101, 1103, 1105, and 1107, respectively, may extend upwardlyfrom bottom wall 1091. Hollow posts 1111, 1113, 1115, and 1117 may beused to receive screws 1112, 1114, 1116, and 1118, respectively, for usein coupling together housing body 1047 and housing cover 1049. As anexample of another such feature, a plurality of walls 1121, 1123, and1125 may extend upwardly from bottom wall 1091 and may extend betweenfirst side wall 1093 and second side wall 1095. The top surfaces ofwalls 1121, 1123, and 1125 may be appropriately shaped to receive a pairof batteries laid thereacross.

As an example of another such feature, a plurality of bosses 1131, 1133and 1135 may extend upwardly from bottom wall 1091 and may beappropriately arranged to receive the bottom end of motor 1057. As anexample of another such feature, a pair of walls 1137 and 1138 mayextend upwardly from bottom wall 1091 proximate to a recess 1141 formedin first side wall 1093. Walls 1137 and 1138 may jointly define a space1139 that may be used to slidably receive a portion of locking clip1055. Wall 1137 may also be slotted to receive a portion of a detentclip 1056 used to support control device 1053. As an example of anothersuch feature, an embossment 1042 extending upwardly from bottom wall1091 may be positioned in space 1139 for use in engaging a spring usedto bias locking clip 1055. As an example of another such feature, a wall1143 may extend upwardly from bottom wall 1091 and may extend betweenfirst side wall 1093 and second side wall 1095. Wall 1143 may beappropriately dimensioned so that its top surface may provide mechanicalsupport to a circuit board of control device 1053 seated thereon.

Housing cover 1049, which is also shown separately in FIGS. 49(a)through 49(e), may be a unitary structure molded or otherwise fashionedfrom a suitably strong material, such as a suitable polymer, metal orother material. Housing cover 1049, which may take the form of agenerally rectangular inverted trough, may be shaped to include a topwall 1147, a first side wall 1149, a second side wall 1151, a first endwall 1153, a second end wall 1155, and an open bottom. Housing cover1049 may be appropriately dimensioned relative to housing body 1047 sothat housing cover 1040 may be secured to housing body 1047 to jointlydefine a cavity for receiving one or more components of pump 1033. Aplurality of walls, embossments and other structural features may extendfrom or otherwise be provided in top wall 1147 of housing cover 1049. Asan example of one such feature, a plurality of hollow posts 1161, 1163,1165, and 1167 may extend downwardly from top wall 1147 and may bepositioned so that screws 1112, 1114, 1116, and 1118 inserted throughhollow posts 1111, 1113, 1115, and 1117 of housing body 1047 may bereceived therein, whereby housing cover 1049 and housing body 1047 maybe joined together. Hollow posts 1161, 1163, 1165, and 1167 may beinternally threaded to receive screws 1112, 1114, 1116 and 1118 or mayhave mounted therewithin internally threaded sleeves (not shown) thatmay threadingly engage screws 1112, 1114, 1116, and 1118.

As an example of another such feature, a plurality of hollow posts 1171and 1173 may extend downwardly from top wall 1147 end may be positionedso that screws (not shown) inserted through a circuit board of controldevice 1053 may be received therein, whereby the circuit board may becoupled to housing cover 1049. Hollow posts 1171 and 1173 may beinternally threaded to receive such screws or may have mountedtherewithin internally threaded sleeves (not shown) that may threadinglyengage such screws. As an example of another such feature, a transverseopening 1179 may be provided in top wall 1147 of housing body 1047, anda collar 1181 surrounding transverse opening 1179 may extend upwardly ashort distance from top wall 1147. Transverse opening 1179 and collar1181 may be appropriately dimensioned for gear 1059 to extend upwardlytherethrough. As an example of another such feature, a plurality ofwalls 1185, 1187, 1189, and 1191 may extend downwardly trout top wall1147 and may be appropriately arranged to collectively define acompartment in which a portion of motor 1057 may be received.

As an example of another such feature, top wall 1147 may be shaped toinclude a first depression 1193 and/or a second depression 1195. Firstdepression 1193 may be appropriately sized and shaped to matinglyreceive syringe body 1041. Second depression 1195 may be appropriatelysized and shaped to matingly receive adaptor 1034. More specifically,second depression 1195 may comprise a first side portion 1201, a secondside portion 1203, and a central portion 1205. First side portion 1201may be sloped downwardly towards central portion 1205 and may be shapedto include an upward projection 1211. Second side portion 1203 may besloped downwardly towards central portion 1205 and may be shaped toinclude an upward projection 1213. Central portion 1205 may extenddownwardly below first side portion 1201 and second side portion 1203and may be shaped to include an opening 1215 through which a portion oflocking clip 1055 may be removably inserted. A pair of walls 1221 and1223 may extend downwardly from the underside of top wall 1147 proximateto a recess 1224 formed in first side wall 1149 and may be used todefine a space 1225 that may slidably receive a portion of locking clip1055. Walls 1221 and 1223 may be stepped or otherwise shaped to delimitthe sliding movement of locking clip 1055 in space 1225. As an exampleof another such feature, one or more ribs 1231 may extend downwardlyfrom top wall 1147 to engage a circuit board of control device 1053.

As an example of another such feature, top wall 1147 may be providedwith one or more transverse openings (not shown) that may serve aswindows to LEDs or other visual indicators on control device 1053 thatsystem 1001 is being operated in an infusion mode. Additionally oralternatively, top wall 1147 may be provided with one or more transverseopenings (not shown) that may serve as windows to LEDs or other visualindicators on control device 1053 that system 1001 is being operated inan aspiration mode. As can be appreciated, instead of providingtransverse openings in top wall 1147 to serve as windows, housing cover1049 may be made of a transparent or translucent material

Power source 1051 may comprise one or more conventional batteries and,more specifically, may comprise one or more conventional disposable AAAbatteries. Although power source 1051 is shown in the present embodimentas consisting of two batteries 1241 and 1243, power source 1051 couldhave as few as one battery or as many as three or more batteries.

Control device 1053 may be in the form of a printed circuit board 1251that may be coupled to the underside of housing cover 1049 in the mannerdiscussed above. Printed circuit board 1251 may be configured to controlthe actuation of motor 1057 based on the actuation of foot pedalassembly 1009. Printed circuit board 1251 may additionally be configuredin any of the manners disclosed herein to cause motor 1057 to stop, evenif foot pedal assembly 1009 is being actuated, when the fluid pressurewithin the fluid path exceeds a predetermined threshold. For example,printed circuit board 1251 may comprise a current sensing circuit, aresistor and a shut-off switch that are arranged as described above inconnection with control device 111′ of FIG. 21 . Printed circuit board1251 may additionally be equipped with one or more LEDs 1255 and 1257 orother indicators that may be used to provide visual or other indicationthat system 1001 is being operated in an infusion mode and/or may beequipped with one or more LEDs 1259 and 1261 or other indicators thatmay be used to provide visual or other indication that system 1001 isbeing operated in an aspiration mode. As a means of distinguishing theinfusion mode from the aspiration mode, LEDs 1255 and 1257 may emitlight of a first color or colors and LEDs 1259 and 1261 may emit lightof a second color or colors that are different from the first color orcolors. Batteries 1241 and 1243 may be coupled to the underside ofprinted circuit board 1251 by conventional means, such as a conductiveclip, and may be supported by walls 1121, 1123 and 1125 of housing body1047.

Locking clip 1055, which is also shown separately in FIGS. 50(a) through50(d), may be a unitary structure molded or otherwise fashioned from asuitably strong material, such as a suitable polymer, metal or othermaterial. Locking clip 1055 may include a block 1271 of generallyrectangular shape. Block 1271, in turn, may have a front 1273, a rear1275, a top 1277, a bottom 1279, a first side 1281, and a second side1283. Rear 1275 may be slightly enlarged relative to the other surfacesof block 1271 so as to provide a peripheral lip 1285. Locking clip 1055may additionally include an arm 1291 that may extend rearwardly fromrear 1275 of block 1271. A finger 1293 may extend at an angle, forexample, generally perpendicularly, from the rear end of arm 1291.Finger 1293 may be bent forwardly to form a pawl 1295. Locking clip 1055may further include a block 1297 extending rearwardly from rear 1275 andbelow arm 1291. A post 1299 may extend rearwardly from block 1297generally parallel to and below arm 1291. Post 1299 may be used to mounta coil spring 1301 coaxially thereover.

Locking clip 1055 may be appropriately dimensioned so that block 1271may be slidably mounted within an opening formed jointly by recess 1141of housing body 1047 and recess 1224 of housing cover 1049, with block1271 being retained within said opening by peripheral lip 1285. Post1299 of locking clip 1055 may be slidably mounted within space 1139between walls 1137 and 1138 of housing body 1047 and may be biased inthe direction of recesses 1141 and 1224 by coil spring 1301, whosedistal end may engage embossment 1042. Arm 1291, finger 1293 and pawl1295 may be appropriately dimensioned so that, when coil spring 1301 isnot being compressed as a result of an operator's depression of block1271, pawl 1295 may extend sufficiently through opening 1215 in housingcover 1049 to lockably engage a portion of adaptor 1034 sitting incentral portion 1205 of second depression 1195 and so that, when coilspring 1301 is sufficiently compressed due to an operator's depressionof block 1271, pawl 1295 may be withdrawn sufficiently from opening 1215so as not to engage adaptor 1034, thereby enabling adaptor 1034 to bewithdrawn from pump 1033.

Motor 1057, which may be, for example, a conventional bi-directional DCmotor, may be electrically coupled to control device 1053 by wires (notshown) or other suitable means. Motor 1057 may comprise a rotatableshaft 1371, which may be generally D-shaped in transverse cross-section.Motor 1057 may be appropriately dimensioned to be securely received bybosses 1131, 1133 and 1135 of housing body 1047 and by walls 1185, 1187,1189 and 1191 of housing cover 1049.

Gear 1059, which is also shown separately in FIGS. 51(a) and 51(b), maybe a unitary structure molded or otherwise fashioned from a suitablystrong material, such as a suitable polymer, metal or other material.Gear 1059 may be appropriately shaped to include a base portion 1381 anda toothed wheel 1383. Base portion 1381 may include a longitudinallyextending bore 1384, which may be appropriately dimensioned to receiverotatable shall 1371 so that gear 1059 may be coupled to shaft 1371 forrotation. Gear 1059 may be fixed to shaft 1371 by means of a hex socket1391 inserted into a hole 1393 in base portion 1381. Toothed wheel 1383may be appropriately dimensioned so that, when syringe 1031 is coupledto pump 1033, gear 1059 is brought into engagement with rack 1083 ofsyringe plunger 1043, and the rotation of gear 1059 causes syringeplunger 1043 to be moved translationally relative to syringe body 1041,resulting either in the expulsion of fluid from syringe body 1041 or inthe suctioning of fluid into syringe body 1041, depending on thedirection in which syringe plunger 1043 is moved.

Pump 1033 may additionally include a power on/off switch (not shown).

Adaptor 1034, which may be fixedly and coaxially mounted on syringe 1031and which may be used to mechanically couple/decouple syringe 1031to/from pump 1033, may comprise a top portion 1401 and a bottom portion1403. Top portion 1401 and bottom portion 1403 may be complementarilyshaped and may be joined to one another by adhesive, welding, mechanicalmeans, or other suitable means. Top portion 1401, which is also shownseparately in FIGS. 52(a) through 52(c), may be a unitary structuremolded or otherwise fashioned from a suitably strong material, such as asuitable polymer, metal or other material. Top portion 1401 may beshaped to include a top wall 1403, a first side wall 1405, a second sidewall 1407, a first end wall 1409, a second end wall 1411, and an openbottom. Top wall 1403 may be shaped to conform to the shape of syringeflange 1073. First side wall 1405 may include a recess 1415 that may beshaped to receive a first finger of an operator for use to handlingadaptor 1034, and second side wall 1407 may include a recess 1417 thatmay be shaped so receive a second finger of an operator for use inhandling adaptor 1034. A plurality of internal walls 1421 and 1423 mayextend downwardly from top wall 1403 and may extend from first side wall1405 to second side wall 1407. Internal wall 1421 may run parallel tofirst end wall 1409 and may define a first compartment 1425 with topwall 1403, first end wall 1409, first side wall 1405 and second sidewall 1407. Internal wall 1421 may include a recess 1427, and first endwall 1409 may include a recess 1429. Recesses 1427 and 1429 may beshaped to matingly receive syringe body 1401 thereacross. Internal wall1423 may ran parallel to internal wall 1421 and may define a secondcompartment 1431 with top wall 1403, internal wall 1421, first side wall1405 and second side wall 1407. Second compartment 1431 may be shaped tomatingly receive a portion of syringe flange 1073. Internal wall 1423may include a recess 1433 and second end wall 1411 may include a recess1435. Recesses 1433 and 1435 may be shaped, to matingly receive syringeplunger 1043 in such a manner that syringe plunger 1043 may be slidablymounted thereacross.

Bottom portion 1403, which is also shown separately in FIGS. 53(a)through 53(c), may be a unitary structure molded or otherwise fashionedfrom a suitably strong material, such as a suitable polymer, metal orother material. Bottom portion 1403 may be shaped to include a bottomwall 1453, a first side wall 1455, a second side wall 1457, a first endwall 1459, a second end wall 1461, and an open top. Bottom wall 1453 mayinclude a transverse opening 1463 that may be appropriately dimensionedand positioned to permit gear 1059 to pass therethrough so that gear1059 may engage rack 1083 of syringe plunger 1043. Bottom wall 1453 mayadditionally include a projection 1465 extending downwardly therefrom.Projection 1465 may be shaped to mate with central portion 1205 ofsecond depression 1195 of housing cover 1049. Moreover, projection 1465may include an opening 1466 that may mate with pawl 1295 of locking clip1055 so that adaptor 1034 may be lockingly mounted on pump 1033. Bottomwall 1453 may further include a pair of hingedly mounted spring tabs1467 and 1469. Spring tabs 1467 and 1469 may be appropriately shaped tomate with first side portion 1201 and second side portion 1203,respectively, of housing cover 1049 and to resiliently engageprojections 1211 and 1213, respectively.

First side wall 1455 of bottom portion 1403 may include a recess 1471that may be aligned with recess 1415 of top portion 1401 to receive afirst finger of an operator for use in handling adaptor 1034, and secondside wall 1457 may include a recess 1473 that may be aligned with recess1417 of top portion 1401 to receive a second finger of an operator foruse in handling adaptor 1034. A plurality of internal walls 1485 and1487 may extend upwardly from bottom wall 1453 and may extend from firstside wall 1455 to second side wall 1457. Internal wall 1485 may runparallel to first end wall 1459 and may define a first compartment 1489with bottom wall 1453, first end wall 1459, first side wall 1455 andsecond side wall 1457. Internal wall 1485 may include a recess 1491, andfirst end wall 1459 may include a recess 1493. Recesses 1491 and 1493may be shaped to matingly receive syringe body 1401 thereacross.Internal wall 1487 may run parallel to internal wall 1485 and may definea second compartment 1495 with bottom wall 1453, internal wall 1485,first side wall 1455 and second side wall 1457. Second compartment 1495may be shaped to matingly receive a portion of syringe flange 1073.Internal wall 1487 may include a recess 1497 and second end wall 1461may include a recess 1499. Recesses 1497 and 1499 may be shaped tomatingly receive syringe plunger 1043 in such a manner that syringeplunger 1043 may be slidably mounted thereacross.

Foot pedal assembly 1009, which is also shown separately in FIGS. 54(a)and 54(b), may comprise a printed circuit board 1501, a plurality ofresiliently-compressible tubes 1503-1 and 1503-2, a plurality of plugs1505-1 and 1505-2, and an electrical cable 1507. Each of the foregoingcomponents will now be discussed further below.

Printed circuit board 1501 may comprise a circuit board 1511. Circuitboard 1511, in turn, may be an elongated member having a first portion1513 and a second portion 1515. Circuit board 1511 may be sufficientlyflexible to enable first portion 1513 to be flexed towards secondportion 1515 or vice versa. Due or more pressure-actuated switches 1517may be mounted on first portion 1513, and one or more pressure-actuatedswitches 1519 may be mounted on second portion 1515. Switches 1517 and1519 may be configured so that actuation of at least one of switches1517 may cause pump 1033 to be operated in an infusion mode, andactuation of at least one of switches 1519 may cause pump 1033 to beoperated in an aspiration mode, or vice versa.

Resiliently-compressible tubes 1503-1 and 1503-2 may be resilientmembers molded or otherwise fashioned from blown polyethylene or asimilarly suitable material that quickly returns to its original shapeafter being radially compressed. Tube 1503-1 may be appropriatelydimensioned to receive first portion 1513 of circuit board 1501, andtube 1503-2 may be appropriately dimensioned to receive second portion1515 of circuit board 1502. Preferably, tubes 1503-1 and 1503-2 areslightly undersized relative to printed circuit board 1501 so that, whenprinted circuit board 1501 is inserted thereinto, tubes 1503-1 and1503-2 become slightly distended by printed circuit board 1501. In thismanner, regardless of the at-rest rotational position of tubes 1503-1and 1503-2 on a floor or similar surface, when an operator steps on tube1503-1 or tube 1503-2, the stepping of the operator's foot on theapplicable tube rapidly ensures a suitable orientation of printedcircuit board 1501 for actuation of the desired pressure-actuatedswitches. Tubes 1503-1 and 1503-2 may be generally identical to oneanother in size, shape, construction, and appearance or may be markedand/or colored differently to denote the different effects resultingfrom their being depressed, for example, infusion or aspiration. As canbe appreciated, although tubes 1503-1 and 1503 are shown in the presentembodiment as directly contacting one another in an end-to-endarrangement, tubes 1503-1 and 1503-2 may be spaced apart from oneanother, for example, using a suitable tubular member. In addition, itshould be appreciated that tubes 1503-1 and 1503-2 may be replaced witha single tube having a length equal to the combined lengths of tubes1503-1 and 1503-2.

Plug 1505-1, which may be used to plug the outside end of tube 1503-1,may be mounted in tube 1503-1 with an interference fit and an adhesive.Plug 1505-2, which may be used to plug the outside end of tube 1503-2,may be mounted in tube 1503-2 with an interference fit and an adhesive.Plug 1505-1 may be shaped to include a longitudinal bore 1521, throughwhich a first end 1523 of cable 1507 may be inserted. First end 1523 ofcable 1507 may be coupled to printed circuit board 1501 and may besecured thereto using a cable tie 1525. A second end 1526 of cable 1523may be provided with an audio plug 1527, which may be removably coupledto a plug receptacle 1528 mounted on printed circuit board 1251 in pump1033 and accessible through an opening 1529 of housing cover 1049.

To prepare system 1001 for the injection of fluid into a patient,syringe/pump 1007 may first be prepped. This may be-done, preferablywhile the combination of syringe 1031 and adaptor 1034 is decoupled frompump 1033, by manna by refracting syringe plunger 1043 within syringebody 1041 while male luer connector 1075 or a fluid conducting memberattached thereto is inserted into the desired fluid. The combination ofsyringe 1031 and adaptor 1034 may then be coupled to pump 1033 first byaligning-adaptor 1034 with pump 1033 so that opening 1463 of adaptor1034 is positioned over gear 1059 of pump 1033 and so that projection1495 of adaptor 1034 is positioned over central portion 1205 of seconddepression 1195 of pump 1033. Next, adaptor 1034 may be brought intolocking engagement with pump 1033 by inserting projection 1465 ofadaptor 1034 down into central portion 1205 of second depression 1195until pawl 1295 of locking clip 1055 snaps-locks into opening 1466 ofprojection 1465. The aforementioned snap-locking together of adaptor1034 and pump 1033 is accompanied by the engagement of gear 1059, whichis inserted through opening 1463 of adaptor 1034, with rack 1083 ofplunger 1043. With syringe/pump 1007 thus prepped, infusion needleassembly 1003 may be fluidly coupled to syringe body 1041 if it has notalready been so coupled. Infusion needle 1017 may then be inserted intothe patient at a desired location. To dispense fluid from syringe 1031into the patient, the operator steps onto tube 1503-1 to actuate atleast one of switches 1517 positioned therewithin (or, if tube 1503-1 isconfigured for aspiration and tube 1503-2 is configured for infusion,the operator steps on tube 1503-2 to depress at least one of switches1519 positioned therewithin). The actuation of at least one of switches1517 causes LEDs 1255 and 1257 to emit light and simultaneously causesmotor 1057 to drive the rotation of gear 1059 against rack 1083 suchthat plunger 1043 causes the dispensing of fluid from syringe 1031. Toaspirate fluid from the patient, the operator steps onto tube 1503-2 toactuate at least one of switches 1519 positioned therewithin (or, iftube 1503-1 is configured for aspiration and tube 1503-2 is configuredfor infusion, the operator steps on tube 1503-1 to depress at least oneof switches 1517 positioned therewithin). The actuation of at least oneof switches 1519 causes LEDs 1259 and 1261 to emit light andsimultaneously causes motor 1057 to drive the rotation of gear 1059against rack 1083 such that plunger 1043 causes fluid to be drawn intosyringe 1031. If, at any time during which at least one switch 1517 orat least one switch 1519 is actuated, the pressure in the fluid pathexceeds the predetermined threshold, control device 1053 automaticallystops the operation of motor 1057.

To remove the combination of syringe 1031 and adaptor 1034 from pump1033, one may slide block 1271 of locking clip 1055 sufficiently towardsthe interior of pump 1033 so that pawl 1295 of locking clip 1055 iswithdrawn from opening 1466 of projection 1465 and, at the same time,may lift the combination of syringe 1031 and adaptor 1034 away from pump1033.

If desired, one or more components of system 1001 and, in fact,preferably all of the components of system 1001, except possibly forhandheld ultrasound imager 1005 and pump 1033, may be disposable,single-use items.

As noted above, control device 1053 may be in the form of a controlcircuit that senses the motor current using a series resistor, such as a1 ohm series resistor. The sensed motor current is then used as a proxyfor the fluid pressure in the syringe chamber. This pressure is a directresult of the driving force of the plunger and is determined by thegear, the rack and the torque of the motor. The torque performance ofthe motor is fairly linear with the current drawn by the motor. Thecorrespondence of motor current to the resultant syringe pressure issufficient to determine the infusion pressure during procedures likeanesthesia infusion procedures. By limiting the operation of the motorto an acceptable current range, an acceptable range of infusion pressurecan be maintained.

An alternative to the foregoing arrangement is to measure the pressurein the syringe chamber directly by modifying the seal and the end capdesign of the syringe plunger. More specifically, a space can bedesigned between the seal and the end cap such that the gap distancebetween the proximal surface of the seal and the distal surface of theplunger end cap is known when the syringe is empty and without fluid.When the syringe contains fluid, the syringe can be operated so that thechamber fluid pressure is above atmospheric. In response to theincreased syringe fluid pressure on the distal surface of the seal, theshape of the seal changes in such a way as to reduce the gap distancebetween the seal and the plunger end cap. This change in the gapdistance directly correlates with the pressure in the fluid of thesyringe.

The aforementioned gap distance may be measured by any of a number ofdifferent techniques. To measure the gap distance electrically, twoconductive paths may be provided from the seal and the plunger to runalong the full length of the plunger to the syringe collar withelectrically conductive wipers, subsequently terminating at the printedcircuit board in the pump housing to control the fluid pressure byshutting off the motor current and torque.

The foregoing gap displacement may be detected as either a binary orcontinuous analog signal.

One example of a binary embodiment tor detecting gap displacement isshown in FIG. 55 as part of syringe 1601. As can be seen in FIG. 55 ,the proximal surface of a seal 1603 may be provided with a stiffpressure plate 1605 which pushes against a click switch 1607 embeddedits a distal end cap 1609 of a plunger 1611. When a threshold occlusionpressure exists and the gap is closed, pressure plate 1605 activatesclick switch 1607, making an audible sound that indicates to an operatorthat the threshold pressure has been exceeded.

As another example of a binary embodiment, the proximal surface of theseal may be made of or coated with an electrically conductive materialwhich shorts out contacts embedded in the distal end can of the plunger.When a threshold occlusion pressure exists and the gap is closed, theconductive surface closes the contacts. The closure event is passedalong the conductive paths from the plunger to the collar to the printedcircuit board, where the control circuitry terminates the motor currentand torque.

One example of an analog embodiment for detecting gap displacement isshown in FIG. 56 as part of syringe 1701. As can be seen in FIG. 56 ,the proximal surface 1703 of the seal 1705 and the end cap 1707 of theplunger 1709 may provide a sealed pneumatic chamber 1710 for detectingthe fluid pressure inside the syringe body. A pneumatic channel 1711 maybe created from this sealed chamber and connected to an inexpensivesmall pneumatic sensor device 1713 mounted on the rails of the plunger1709. Such pneumatic sensor devices of this type are currently used forconsumer blood pressure measurement medical devices. The electricalsignals from such a device may be passed along the conductive paths fromthe plunger to the collar to the printed circuit board, where theelectrical signals are converted to pressure to determine whether toterminate the motor current and torque.

Another example of an analog embodiment for detecting gap displacementis shown in FIG. 57 as part of syringe 1801. As can be seen in FIG. 57,the proximal surface of the seal 1803 may have an electricallyconductive element 1507 mounted thereon, and the end cap 1804 of theplunger 1805 may have an electrically conductive element 1809 mountedthereon. Elements 1807 and 1809 may be used to detect the gap distanceeither capacitively (i.e., as two parallel electrical plates) orinductively (i.e., as coupling between two parallel coils). Thecapacitive or inductive electrical signals may be passed along theconductive paths from the plunger to the collar to the printed circuitboard, where the capacitive or inductive signals is processed todetermine whether to terminate the motor current and torque.

Another example of an analog embodiment for detecting gap displacementhas conductive elements that may be resistive, thereby allowing thevariation in the contact area of the two surfaces its response to theseal pressure compliance to correspond to the syringe fluid pressure.The surface of the end cap may be flat, and the surface of the seal maybe convex with a sphericity proportional to the fluid pressure andcompliance on the seal. The resultant resistance between the twosurfaces in contact varies in proportion to the fluid pressure. Theelectrical signals from this resistive sensor may be passed along theconductive paths from the plunger to the collar to the printed circuitboard, where the resistance is processed to determine whether toterminate the motor current and torque.

Still another arrangement is shown in FIGS. 58(a) and 58(b) as syringe1901. Syringe 1901 may comprise a syringe body 1903, a syringe plunger1905, a seal 1907, an adaptor top portion 1909, an adaptor bottomportion 1911, a pressure sensing module 1913, bus bars 1915 and 1917,and spring contacts 1919 and 1921.

In the foregoing analog embodiments, continuous variable measurement canalso provide additional information about fluid characteristics.Microcomputer software processing could be added so the printed circuitboard, allowing real-time data to be generated for an operator, such asflow rates, actual pressure monitoring and fluid injection velocity.Procedure information may also be maintained for patient records.

It should be noted that the present invention is not to be limited toapplications involving nerve blocks using regional anesthesia. Rather,the present invention may also be used in joint injections (tendons ormuscles), deep vascular access, suction biopsies, aspiration of bodilyfluids, intralesional injections for tumor chemotherapy treatments oftumors, and general controlled injection or aspiration of fluids of thehuman body. The present invention also has applications in dentistry andpediatrics. In dentistry, initial injection pressures of 100 mmHg (2psi) or less have been found to correlate with less pain and anxietycompared to higher injection pressures (300 mmHg (5 psi) and greater)(see Kudo, “Initial Injection Pressure for Dental Local Anesthesia:Effects on Pain and Anxiety,” Anesthesia Progress, 52(3); 95-101 (2005),which is incorporated herein by reference.

It should also be noted that an alternative to the use of abi-directional drive mechanism in any of the above embodiments isaspiration by means of an evacuated aspiration vial.

The embodiments of the present invention described above are intended tobe merely exemplary and those skilled in the art shall be able to makenumerous variations and modifications to if without departing from thespirit of the present invention. All such variations and modificationsare intended to be within the scope of the present invention as definedin the appended claims.

We claim:
 1. A system for controllably administering fluid to a patientand/or for controllably withdrawing fluid from the patient, the systemcomprising: a syringe comprising: a plunger with a first mechanicalinterface; and a syringe body for holding fluids; and a pump comprisinga second mechanical interface which interfaces with the plunger of saidsyringe via the first mechanical interface thereby to: advance theplunger relative to the body of said syringe to controllably administerfluid to the patient; and to retract the plunger of said syringerelative to the body of said syringe to controllably withdraw fluid fromthe patient, and a hands free user input configured to connect to thepump and to allow a user to operate the pump to start and stop thetranslation of the plunger and also wherein the hands free user input isconfigured to allow the user to select and operate the pump to translatethe plunger relative to the syringe body in two opposing directions,wherein the syringe includes a mechanical connector configured such thatthe syringe is attachable to and detachable from the pump and whereinwhen detached or attached to the pump the plunger of the syringe may beoperated manually by the user.
 2. The system of claim 1 comprising: acontrol device for determining and controlling a pressure in a fluidpath wherein said fluid path is in fluid communication with the syringebody and the patient.
 3. The system of claim 2 wherein the controldevice determines and controls pressure in the fluid path so that thepressure in the fluid path does not exceed a predetermined threshold. 4.The system of claim 3 comprising a pressure relief valve provided in thefluid path wherein the control device controls pressure in the fluidpath using the pressure relief valve.
 5. The system of claim 3comprising a pressure sensor arranged to detect the pressure in thefluid path and wherein the control device is configured to instruct thepump to stop pumping when pressure in the fluid path exceeds thepredetermined pressure threshold.
 6. The system of claim 3 wherein thepredetermined pressure threshold is selected to minimise nerve damage.7. The system of claim 3, wherein the second mechanical interfaceincludes a rotatable gear configured to interface with and operate theplunger of the syringe.
 8. The system of claim 1 wherein the user inputis configured such as to allow operation of the pump by foot.
 9. Thesystem of claim 1 wherein the user input is connected to the pump by asingle wire which transports a signal from the user input to the pump,wherein the signal is based on an input of the user into the user input.